Establishing the direction of the impact impulse allows you to find out. Tanner collision with an accident. Collision of vehicles

The TC collision location can be established on the grounds recorded in the case file (inspection protocols, circuits, photographs). The informativeness of these signs is different. Some make it possible to establish a collision's place with sufficient accuracy, others - approximately, others can only be an additional confirmation of the location of the collision location defined by other paths. The conclusion about the location of the collision location should be based on the study of the totality of all such signs.

The main features that establish the place of collision of the CU, can be divided into 5 groups: traces of the movement of the vehicle; traces of moving discarded objects; the location of the objects separated from the CU; The location of the TC after the incident; TC damage obtained in collision.

The first trace group is characterized by the following features:

A sharp deviation of the track of the wheels from the initial direction (with an eccentric blow on the vehicle or by the front wheel);

The side shift of the unlocked wheel or side shift of the track of the wheel (most accurately determines the position of the vehicle during the collision);

The termination of the thread of the SEA arises when it is hit as a result of an additional load on the wheel;

The formation of a trace of the wheel slip when the deformable parts are jammed;

The formation of the track of the wheels when air outputs from the tire, damaged by impact;

Traces of wheels of both vehicles before collision (determined the position of the vehicle at the time of the collision at the place of their intersection, taking into account the mutual location when hit);

Traces of friction of parts of the vehicle on the road coating during body deformation or when the running part is destroyed at the moment of impact.

The second trace group is characterized by the following signs:

Traces of heavy objects (separated from the vehicle parts, fallen cargo, etc.) in the form of scratches, entritations. At the beginning of their formation, they have the direction to the place of separation from the CU (close to the clash).

The definition of a collision site at the place of crossing the directions of such traces is the more accurate than them is set.

The third trailer group is characterized by the location of the objects separated from the CU:

Screened land (dirt) with shock deformable and other lower surfaces of the vehicle. The scree of the smallest particles remains almost directly at the point of impact. Larger particles can be shifted by inertia in the direction of movement of the vehicle. To more accurately establish the location of the vehicle at the moment of strike, it is necessary to know what the TCs belongs to the fallen land;

Pack of dispersion of paintwork particles (LCP). These particles, having a small inertia, fall into the immediate vicinity of the collision place and partially dissipate in the direction of the TS movement after impact. It is possible to displace them with air flows;

Site of glass fragments. It allows you to approximately judge about the collision site, when their free fall did not prevent the surfaces from which ricozelation could occur. The location of the greatest number of objects separated from the CU during the strike of objects makes it possible to judge the place of collision approximately, taking into account their possible offset from the collision seat after impact. The location of individual large parts, as a rule, cannot be a sign for establishing a collision location.

The fourth trailer group is the location of the TC after the incident:

The location of both TCs after the longitudinal counter collision on one side of the roadway is a sign that the collision occurred on the same side of the carriageway;

The location of both TCs in the immediate vicinity of the collision location when moving in the counter direction parallel courses before the collision allows you to determine the transverse shift of the center of gravity of them from the place where the blow was applied.

Fifth group of traces- TC damage resulting from a collision:

The location of the TC damage from contact with each other makes it possible to determine their mutual location at the time of the collision and refine the place of collision, if the location and direction of movement of one of them are set at the time of the collision;

The direction of deformations, which determines the direction of the blow, allows you to establish a possible offset of the TC from the place of the collision and by its location after the incident refer to the place of collision;

The collision of vehicles can occur with the following model situations - their seven:

• - rear clash - a collision with the back of the stopped car, its varieties;
• - a counter collision - cars follow exactly all and hit the front parts;
• - an angular collision - a blow of one car into an angle of another when the length of the contacting surfaces of cars during the blow is 15 cm;
• - lateral collision - the collision of the car by the sides, the length of the contacting surfaces of the car is less than 15 cm;
• - Cross Collision - Cars face at right angles;
• - collision of several vehicles;
• - a collision of autotaging with a trailer and semi-trailer.

Based on the analysis of damage, the type of collision is determined, which indicates a configuration at the time of the collision. Before the collision, each car moves in its direction. In a collision, cars can move and rotate to the positions in which they found themselves at a complete stop and which have nothing to do with their position when colliding.

After the rear collision, cars can stop in the detachment, if it happened in motion or bounce one from the other, if one car stood. One car will damage the back, in the other - the front part. Traces of damage on one car will coincide with the damage of the other.

In general, road transport crimes are a specific kind of crimes representing the result of a failure in the action of the "Man - Car - Road-Wednesday system". "The complexity of the interaction of elements of those included in this system determines the objective and subjective nature of the difficulties of the investigative process. Therefore, without the use of modern judicial - autothechnical knowledge, the successful disclosure and investigation of road crimes "Sidorov E.T. Improving the reliability of the judicial and technical expertise, by refining its initial data // Investigator. - Number 3. - 1999, p. 45 .. After all, "the correctness of the name of the examination and the wording of the issues by the investigator during its purpose can play crucial importance when considering a criminal case in court. This is especially important when investigating road crimes when the result of the examination is sometimes the evidence on which all the investigation is based. ... When appropriating any examination, the investigator should clearly represent what special knowledge is required to resolve the issues of them. In case, to permit any question, knowledge is required in several areas of scientific knowledge, it is necessary to appropriate an integrated examination "Koszovich A.A. Questions of appointment and production of autotechnical examination // Investigator. - №12. - 1999, p. 35 ..

The following type is a counter collision, it happens quite rare, since drivers seek to dodge from a counter strike. But they occur and have their own characteristics.

With such collisions, cars stop at the site of the collision or bounce on an equal distance if their weight and speed were the same. With unequal weight and speed, the car is easier or moving at a lesser speed will be discarded back from the collision. With such a collision, cars do not rotate and the fragments occupy a small area of \u200b\u200bthe road. The main question in the collision is to find out which side the collision occurred. The place of collision in this case is determined by the location of the cars and in the footsteps of the slide of the wheels to the strike and after it, taking into account the listed features.

In the literature there is evidence that: "Analysis of a large number of road accidents allowed me to establish that for every 100 accidents account for about 250 reasons and related facts.

In the segment of time, directly by the preceding road accident, and in the process of its development, the influence of each of the reasons is irregular. In each phase of the development of an accident, one main, leading reason can be distinguished. In the subsequent phases of the incident, this reason can be a secondary, concomitant, and the main thing becomes that in the first phase was a concomitant. When analyzing a road accident, it is necessary to identify all causal relationships. Otherwise, the establishment of the root cause of the incident is difficult, and sometimes impossible. An important value at the same time has the identification of the circumstances preceding the road and transport incident. In many cases, the prerequisites for the accident are created much earlier than the accident.

According to the materials of world statistics, the distribution of the reasons for an accident approximately the following:

• - due to improper actions of man 60-70%;
• - due to the unsatisfactory state of the road and the inconsistencies of road conditions, the nature of the movement of 20-30%;
• - because of the technical malfunction of the car 10-20% »Konoplyanko V.I. Road organization and safety: Textbook for universities. - M.: Transport, 1991, p. sixteen..

The following view is an angular collision, it is the most common accident and has its own characteristics. With such a collision after impact, cars are usually rotated, leaving traces of tires; When colliding with left corners there is a rotation counterclockwise and cars bounce on one of the other; When contacting with right angles - as a rule, clockwise. The radius of the scatter of parts and debris depends on the area of \u200b\u200bcontacting the mass of cars, their speeds, from the state of the road surface. With this collision, the investigator should find out which side of the arc on the axial line there was a collision, as the debris, glass residues, spilled oil and dirt can be scattered on a relatively large area. However, the place of collision can be determined approximately because with this collision every car moves from the place of collision towards its side of the road.

Cross collision is characterized by the fact that traces of braking indicate the movement of cars.

One car dents will be in front of the other - in the other. Traces of sliding tires after a collision will reflect the speed of the vehicle. When considering the cross-collision, the investigator needs to decide which car left first to the intersection. In this case, three options may occur:

• - both left the intersection at a constant speed (without braking);
• - one drove to the intersection at a constant speed, and the other brake;
• - both drove to the intersection and braked.

In the first case, the investigator is necessary: \u200b\u200bto measure the distance from the place (point) of the collision to the lines that limit the intersection, this allows you to determine the speed of cars in the future. Based on the speed, it will be possible to determine the time that it took each car to drive from the border of the intersection to the collision site. The time will indicate which car went to the intersection earlier, which later.

In the second case, the determination of the speed of braking and its length from the border of the intersection to the clash place indicates who went to the intersection first.

In the third case, when both cars to the place of collision were in a state of braking, the length of the braking path will indicate the speed of each of them and who was the first to go to the intersection.

According to the statistics of the collision of vehicles, "takes place as a rule when overtaking by transporting ahead (every tenth), when the standing car (every twelve case), when the vehicle is moved in the extreme left row (every third case). The main reasons: the wrong calculation during the circulation or overtaking, departure to the head of the counter movement, as well as the self-confidence of the drivers. »Automobile transport. №1, 1996 // Ambarcumian V. The causes of road accidents, p. 22-23 ..

Lateral collision, as well as angular, is the most common; In the side collision, damage is usually insignificant and cars stop the drivers themselves. With lateral collision, cars are usually not rotated. Reliable facts indicating the collision location are mud slices that fell off from the wings, glasses fragments and traces of tire slide. The character of scratches and dents of the sidewall of the body, their directions may indicate the direction of the car movement. With such a collision, cars do not move on the opposite side of the road and finding both cars on a particular lane indicates the road strip on which an accident occurred.

An expert study of traces and damage to TC allows you to establish circumstances that determine the second stage of the collision mechanism - the process of interaction in contacting.

The main tasks that can be solved with an expert study of traces and damage to the vehicle are:

1) establishing an angle of the mutual arrangement of TC at the time of the collision;

2) Determination of the point of initial contact for the vehicle.

The solution of these two tasks reveals the relative position of TC at the time of the strike, which allows you to install or clarify their location on the road, taking into account the signs remaining at the scene, as well as the direction of the collision line;

3) Setting the direction of the collision line (direction of the impact pulse - direction of relative speed of convergence). The solution to this problem makes it possible to find out the nature and direction of the TC movement after impact, the direction of the traumatic forces acting on the passengers, the corner of the collision, etc.;

4) determining the corner of the collision (the angle between the directions of the TC movement before the blow). The collision angle allows you to set the direction of movement of one vehicle, if the direction of the other is known, and the amount of TC movement in a given direction, which is necessary when the speed is detected and the displacement of the collision location.

In addition, tasks may arise related to the establishment of the causes and time of damage to individual parts. Such tasks are solved, as a rule, after the removal of damaged parts with TC by comprehensive research by autotechnical, tusological and metallic methods.

Determination of the angle of the mutual arrangement of TC OO according to deformations and traces on Tc with sufficient accuracy possible when blocking shocks when the relative rate of convergence of TC in the locations of their contact drops to zero, i.e. when almost all the kinetic energy corresponding to the rate of rapprochement is spent on deformation .

It is assumed that in a short time for the formation of deformations and deviations of the relative speed of rapprochement, the longitudinal axes of Tc do not have time to change their direction noticeably. Therefore, when combining the contacting surfaces deformed when the pair sections collide, the longitudinal axis Tc will be located under the same angle as at the time of the initial contact.

Therefore, to establish an angle of JSC, it is necessary to find pairs, in contact with the collision in both Tc (dents on one TC, corresponding to specific protrusions on the other, prints of characteristic parts). It should be borne in mind that the selected areas should be rigidly related to the vehicle.

The location of the sections on parts of the vehicle offset, torn during the movement after impact, does not allow to determine the angle of AO, if it is impossible to establish their position on TC with sufficient accuracy at the time of the deformation when the deformation is completed.

The angle of the mutual arrangement of the AO is in several ways.

Determination of the angle of AO with direct comparison of the TC damage. By installing two pairs of contacting areas on TC, located as far as possible from each other, placed TC so that the distances between the contacting sites in both places were the same (Fig. 1.4).

Fig. 1.4. The scheme for determining the corner of the relative position Tc when a collision in two pairs of contacting sites

With direct comparison, the TC is easier and more or rather, you can define contacting points. However, the complexity of delivery in one place of both TCs, when they are not transportable, and the difficulty of placing them relative to each other in some cases can be impractical to the use of this method.

The method of measuring an angle O 0 depends on the nature of the deformations of the vehicle of the vehicle. It can be measured between TC sides if they are not damaged and parallel to the longitudinal axes, between the axes of the rear wheels, between specially laid lines corresponding to the non-deformed parts of the vehicle body.

Determination of the angle of AO in the corners of the deviation of the next object and its imprint.

Often, after a collision, one of the TC remains clear prints of other parts of the other - rims of headlights, bumpers, areas of the radiator cladding, the front edges of the honests, etc.

Measuring the angles of deviation of the plane of the next object on one Tc and the plane of its imprint on the other (angles xi and x?) From the direction of the longitudinal axes of the TS, we define an angle by the formula

where is the angle of the mutual location, counted from the direction of the longitudinal axis of the first TC.

The direction of reference of the angles in the calculations is taken counterclockwise.

Determining the angle of AO for the location of two pairs of contacting sites. In those

there are no prints on the deformed parts of TC, which allow to measure the corners of the deviation of the contacting plane from the longitudinal axis, it is necessary to find at least two pairs of contacting sites located as far as possible from each other.

Measuring the angles of deviation from the longitudinal axes of direct connecting between these areas on each TCL, the angle of AO will determine the same formula as in the previous

case.

When the blow in a collision is sharply eccentric, after the TC is shred to a significant angle, and the depth of mutual introduction is large, TC has time for the deformation time to turn onto (some angle yes, which can be taken into account if high accuracy of the AO angle determination is required.

Approximately the correction value can be determined by the following calculation:

This formula is approximate; It is removed from the conditions of uniform decreased to zero of the relative speed of rapprochement of the centers of gravity Tc in a collision and uniform decrease to zero of the angular velocity of TC by the time of the stop. However, these assumptions cannot give a significant error when counting the value of the angle A 0.

It should be borne in mind that with an eccentric collision, TC can unfold in different directions. In this case, the angles do not need to be determined for both Tc and the amendment is equal to the sum of these angles.

With a turn of TC of the same type (having close by weight) in one direction, the correction is the difference of angles and is very insignificant, so the calculation is inappropriate.

In a collision of a vehicle having a large mass, with an easier angle and is determined only for easier vehicles.

The relative speed (speed of the meeting V 0) is the easiest to determine the grafoanalytic path, building a triangle on two sides and the corner between them (see Fig. 1.3). It is possible to determine it and with the help of calculations:

Example. As a result of the strike, the left headlight of the car number 1 was deployed to the left at an angle to the longitudinal axis. Fighting headlights on the facing of the car's radiator number 2 will be put to the right to the corner

Car speed before collision

Mutual introduction of cars in the direction of impact of 0.8 m.

After hitting the car number 1 shifted without reversal, the car number 2 turned to the angle of їїї 2 \u003d 180 °, advanced to the place of stopping the clutch nkoeff

The interaction of the TC in a collision is determined by the forces arising during contacting. Depending on the configuration of the inactive parts, they arise in different sections at different points in time, varying in magnitude in the process of promotion of TC relative to each other. Therefore, their effect can be taken into account only as an action of the resultant set of pulse vectors of these forces over the period of contacting the vehicle with each other.

Under the influence of these forces, the mutual implementation of the Mutual deformation of the vessels of the vehicle occurs, the speed of the translational movement and its direction changes, the TC turns relative to the centers of gravity.

The interaction forces are determined by a slowdown occurring during impact (acceleration when driving in a population direction), which, in turn, depends on the distance that the vehicle is moving relative to each other in the process of quenching the speed by these forces (in the process of mutual implementation). The more rigid and durable parts were in contact with a collision, the smaller (with other things being equal) there will be a depth of mutual implementation, the greater the slowdown due to a decrease in the speed of the speed in the process of mutual contact.

Studies to determine the mutual location of vehicles at the time of the collision are directly related to the decision of the place of the primary contact and the flow rate of damage. Having determined the place of primary contact on colliding TCs, the expert establishes the direction of deformation of the inactive parts. This is necessary in order for the TC with a comparative study to be located in the same way as at the time of the incident. First of all, the TC under study determines the place of the primary impact, which may be allegedly clarified during the separate study - by the nature and direction of deformations in damage. Finally, the issue is solved during a comparative study of those who participated in the collision of cars.

Traces of primary contact - pair, with counter clasions they are usually localized on the front protruding parts of cars on bumper, headlamps, car wings, radiator; For associated collisions - on the rear speakers of one car and the front protruding parts of the other. So, the presence of a single car broken left headlight, and the other dents in the center of the hood test indicates that these parts are the first to come into contact and the indicated damage are the traces of the primary contact. This conclusion can be confirmed, for example, the presence of paint from the hood of the car on the headlight of another car and the scraping paints of a broken headlight in the place of dents on the hood. The process of interaction in contact is the second stage of the collision mechanism, which is established in the process of expert research of traces and damage to the vehicle.

The main tasks that can be solved with an expert study of traces and damage to the vehicle are:

• 1) establishing the angle of the Mutual Layout of the TC at the time of the collision;
• 2) Determination of the point of initial contact for the vehicle. The solution of these two tasks identifies the mutual location of the TC at the time of the strike, which allows you to install or clarify their location on the road, taking into account the signs remaining at the scene, as well as the direction of the collision line;
• 3) Setting the direction of the collision line (direction of the impact pulse - direction of relative speed of convergence). The solution of this task makes it possible to find out the nature and direction of the TS movement after impact, the direction of the traumatic forces acting on the passengers, the corner of the collision, etc.;
• 4) determination of the collision angle (the angle between the direction of the TC movement before the blow). The collision angle allows you to set the direction of movement of one TC, if the direction of the other is known, and the amount of TC movement in a given direction, which is necessary when the speed of movement and the displacement from the collision location is detected.

In addition, tasks may arise related to the establishment of the causes and time of damage, individual parts. Such tasks are solved, as a rule, after the removal of damaged parts with the CU by comprehensive research by autotechnical, tusological and metallic methods. Determination of the angle of the mutual arrangement of the vehicle on deformations and traces per TC with sufficient accuracy is possible when blocking shocks when the relative rate of approach of the vehicle in the locations of their contact drops to zero, i.e. When almost all the kinetic energy corresponding to the speed of rapprochement is spent on deformation. It is assumed that in a short time formation of deformations and deviations of the relative rate of rapprochement, the longitudinal axes of the vehicle do not have time to change its direction noticeably. Therefore, when combining the contacting surfaces deformed when paired sections, the longitudinal axes of the TC will be located under the same angle as at the time of the initial contact. Therefore, to establish an angle, it is necessary to find pairs, in contact with the collision on both TCs (dents on one TC, corresponding to specific protrusions on the other, prints of characteristic parts). It should be borne in mind that the selected areas should be rigidly related to the vehicle. The location of the sections on parts of the vehicle, displaced in the process of movement after impact, does not allow to determine the angle, if it is impossible to establish their position on the TC at the time of the deformation when the deformation is completed.

The angle of mutual location is in several ways.

1. Determination of angle with direct comparison of TC damage. Having installed two pairs of contacting areas that are located at the highest distance from each other, placed the TC so that the distances between the contacting sites in both places were the same.

With direct comparison, the vehicle is easier and more accurately, you can define contacting points. However, the complexity of delivery in one place of both TCs, when they are not transportable, and the difficulty of placing them relative to each other in some cases can be impractical to the use of this method.

The method of measuring an angle depends on the nature of the deformations of the vehicle of the CU. It can be measured between TC sides if they are not damaged and parallel to the longitudinal axes, between the axes of the rear wheels, between specially laid lines corresponding to the non-deformed parts of the vehicle body.

2). Determining the angle at the corners of the deviation of the following object and its imprint. Often, after a collision on one of the vehicles, there are clear prints of parts of the other - rims of headlights, bumpers, areas of the radiator cladding, the front edges of the hleb and others.

Measuring the angles of deviation of the plane of the next object on one TC and the plane of its imprint on the other (angles x 1 and x 2) from the direction of the longitudinal axes of the TC, the angle of the mutual location is determined by the formula:

L O \u003d 180 + X 1 -X 2

where - L o the angle of the mutual location, counted from the direction of the longitudinal axis of the first TC.

The direction of reference of the angles in the calculations is taken counterclockwise.

3). Determination of an angle in the location of two pairs of contacting sites. In cases where prints are absent on the deformed parts of the vehicle, allowing to measure the corners of the deviation of the contact plane from the longitudinal axis, it is necessary to find at least two pairs of contacting sites located as far as possible from each other.

Measuring the angles of deviations from the longitudinal axes of direct connecting between these sections on each TC, the angle is determined by the same formula as in the previous case.

When the blow during a collision is sharply eccentric, after the TC is hit, the TC is lowered to a significant angle, and the depth of mutual introduction is large, the TC has time for the deformation time to turn on some angle, which can be taken into account on a special procedure if high accuracy of the angle is required.

It should be borne in mind that with an eccentric collision, the vehicle can unfold in different directions. In this case, the angles need to be determined for both TCs and the amendment is equal to the sum of these angles.

With a turn of the TC of one type (having a closer mass) in one direction, the correction is the difference of angles and is very small, so the calculation is impractical.

When a CC collide having a large mass, with an easier angle is determined only for a softer vehicle.

A blow when a collision of the vehicle is a complex short-term process, which lasts hundredths of a second, when the kinetic energy of moving vehicles spends on the deformation of their parts. In the process of formation of deformations, with the mutual implementation of the vehicle, the contact includes various parts, slipping, deforming, destroying at different points in time. At the same time, the interaction forces, variable values \u200b\u200bin different directions arise between them.

Therefore, under the power of interaction, between TCs in a collision (strength force), it is necessary to understand the equal impulses of all elementary interaction forces between the contacting parts from the moment of the initial contact in the collision until the end of the deformation.

Direct, passing through the line of the resultant pulses of the interaction forces, is called the impact line. Obviously, the impact line passes not through the point of the initial contact of the TC in a collision, and somewhere close to the place of impact on the most durable and hard of its area (the wheel, frame, engine), in the direction of which deformations were distributed. Set the point through which the impact line passes, the estimated path is practically not possible, since it is impossible to determine the amount and direction of the pulses of the forces arising during deformation and the destruction of the set of different parts during the collision.

The direction of the impact line on this vehicle is determined by the angle measured from the direction of its longitudinal axis counterclockwise. The magnitude of this angle depends on the direction of the relative velocity of the vehicle at the time of primary contact in the collision and on the nature of the interaction between the sections in contact with the collision.

With blocking collisions, when there is no slipping between the contacting sites and the relative speed of their convergence is quenched during the deformation process, the direction of the blow coincides with the direction of the relative velocity of the vehicle (the rate of approach of the contacting sites) and the overall direction of dismissed parts.

With sliding collisions, when there is slipping between the contacting areas and there are significant transverse components of the interaction forces (friction force) The direction of the impact line deviates from the direction of the relative velocity towards the action of the transverse components of the interaction forces, which contributes to the mutual discard of the CU from the collision location in the transverse direction.

With tangent collisions, when the transverse components of the interaction forces can significantly exceed the longitudinal, the direction of the impact line can be abruptly deflected in the transverse direction, to an even greater degree contributing to the mutual discarding the vehicle in the transverse direction.

Set the calculations by deflecting the impact line from the direction of relative speed with sliding and tangent collisions, it is almost impossible, since it is impossible to take into account the resistance to relative slipping in the transverse direction in the process of mutual introduction of the vehicle during a collision.

Approximately the direction of the impact line in such cases is determined by the general direction of the displacement of the deformed parts of the vehicle, the direction of deformation on the other TC, taking into account the corner of the collision, the direction of turning the vessel after impact, taking into account the location of the strike places in relation to the centers of gravity.

The direction of the relative velocity of this TC is determined by the angle measured from the direction of its longitudinal axis counterclockwise.

The relative velocity of the vehicle is equal to the relative speed of bringing the sections in contact with the collision, but not the speed of rapprochement of the centers of the vehicle, which is the projection of the relative velocity of the vehicle on direct, passing through their gravity centers. The rate of rapprochement of centers of TCs at the moment of collision can be zero or even have a negative value depending on their mutual location and direction of movement.

To determine the value of the change in the vehicle speed as a result of the collision and the subsequent deformation, there is a technique (Patent of the Russian Federation No. 2308078 for the invention "The method of calculating the collision of vehicles"), which is more convenient to disassemble the following example:

As a result of an accident, the 1st car was damaged in the right side;

To measure the magnitude of the transverse deformation as a base from the gas tank hatch to the front top of the right front wing of the car, the white cord was stretched, as can be seen on the photoilustration No. 1 (Appendix A). The cord was stretched so that on an undeformed car, given the bulk of the side surface of the car, it would be obviously a "through" the car. Thus, the magnitude of the transverse deformation at any point between the racks, measured relative to the cord, is knowingly less than the actual deformation value at this point. Next, 12 points were noted on the surface of the car according to the scheme in Fig. 1, and the magnitude of the deformation in each of them was measured using a vertical rail, installed at the cord, as the distance from the rail to the point on the surface of the car.

Figure 1. Measurement of vehicle deformation values \u200b\u200b1.

The resulting measuring the magnitude of the transverse deformation is shown in the table below.

Table 1. Car deformation 1.

Point number
Deformation, see
Point number
Deformation, see

From Table 1 and Photo Film No. 1 (Appendix A) it can be seen that the greatest deformations take place at the height of the threshold and above it, which corresponds to the location of the 2nd car bumper. - 2 car got damage in front;

The external inspection found that the car 2 has damage to the front part in the direction mostly front. At the time of inspection, the car partially disassembled, in particular, the hood was removed, there is no plastic bumper lining, doors, rear bumper and rear lights. The power elements of the front part, like spars and the bumper amplifier were in place. The thickness of the sheet material of the spars is 1mm. Still-up cracks or corrosion traces on the power elements of the car are not detected.

On photo filstration 2 shows the car 2 in front of the right and the diagram of measuring its deformation. At a distance of 320cm from the rear axle of the car, where the deformations and displacements of the design elements were absent, the rail was laid on the floor. On the rail marked 5 points, located at a distance of 38 cm from each other so that the extreme points correspond to the edges of the front part, and the average point is the longitudinal axis of the car. Point numbering is shown on photoillus. Next, the distance from each point to the front of the car along the longitudinal axis was measured by a roulette and amounted to, see Table 2.

Table 2. Car deformation 2.

Point number
Deformation, see

For subsequent analysis and calculation, the results of the car's wheel test of the car 2 are used on the frontal blow to the hard non-deformable barrier at a speed of 56km / h, produced by the certified laboratory in the United States under the NCAP Safety Test Program, the member of which is Russia.

Figure 2. Fragment p.32 Crash test report.

Figure 3. Comparison of car deformations 2 and crash test.

It can be seen that the magnitude of the deformation of the front of the car 2 in an accident only in the middle part is comparable with the validity of the deformation in the crash test, and the left and right of the longitudinal axis of the deformation value significantly exceed the deformations in the crash test. The actual mass of the laboratory vehicle in the crash test was 1321kg, and the actual impact rate was 55.9 km / h. Therefore, energy was spent on the deformation of a laboratory vehicle:

E \u003d 1 / 2hm (V / 3,6) 2 \u003d 1 / 2h1321ch (55.9 / 3,6) 2 \u003d 159254 J;

where E is the energy spent on the deformation, M mass of the car, V- vehicle speed. And the magnitude of the energy spent on the deformation of the car 2 in the accident, there was respectively more than this magnitude.

The rigidity of the car's BOK 1 is less than the stiffness of the front of the car 2, since the magnitude of the strain of the car 1 - 70 cm in the middle part of the right side is greater than the amount of vehicle deformation 2-41cm in the middle of the front part in

k \u003d 70/41 \u003d 1.7 times.

Due to the equality of action to counter the amount of the interaction of cars during their deformation was the same for both cars. Consequently, the energy value (operation of force) spent on the deformation of the car 1, in K times the energy of E 2, spent on the deformation of the car 2, or

E 1 \u003d Ke 2 \u003d 1.7ch159254 \u003d 270732 J,

Where E 1 is the energy spent on the deformation of the car 1, e 2 - the energy spent on the deformation of the car 2.

The actual magnitude of the energy spent on the deformation of the car 1 was greater, as it was more than in the laboratory crash test, the value of the energy costs for the deformation of the car 2 in the accident.

Then the total amount of energy costs for the deformation of both cars in an accident is at least

E \u003d E 2 + E 1 \u003d 159254? + 270732 \u003d 428986 J.

The mass of the car 2 and the driver at the time of the accident was

M 2 \u003d 1315 + 70 \u003d 1385? kg.

Mass of the car 1 and two people at the time of the accident was

M 1 \u003d 985 + 2h0 \u003d 1125? kg.

From here, the speed of the car 2 as a result of a blow to the car 1 changed by no less

DV 2 \u003d 3.6 V (2EM 1 / m 2 (M 2 + M 1)) \u003d

3.6HV (2h428986ch1125 / 1385 h (1385 + 1125) \u003d 60 km / h

Car speed 1 As a result of a car's impact, 2 has changed by no less

DV 1 \u003d 3.6 V (2EM 2 / M 1 (M 2 + M 1)) \u003d

3.7HV (2h428986ch1385 / 1125ch (1385 + 1125) \u003d 74 km / h

This technique allows you to establish the circumstances of the road accident by calculating the collision of vehicles. The technical result is to determine changes in the velocities of objects based on the costs of their kinetic energy for deformation during a collision. The technical result is achieved by the fact that the actual dimensions and shapes of the deformed structural elements are determined, represent the external surfaces of colliding objects in the form of grid models, or internal elements of objects of objects, or a combination of them, solve a physically non-linear problem by repeatedly solving the system of equations, calculate the change in the velocities of objects based on From the cost of their kinetic energy to deformation during a collision.

§ 4. Expert study of the collision process

The main parameters of the collision process

All the main parameters of the collision mechanism in the second stage of the EC process of the EC collision can be divided into two groups: the parameters that determine the change in the velocities of the velocity of the vehicle, and the parameters that determine the mutual location of them at the moment of impact.

The main parameters that determine the change in the speed and direction of the TC movement include the following values:

TC speeds at the moment of initial contact in the collision and;

TC speeds immediately after impact and;

The angle between the directions of movement at the moment of impact (angle of the meeting);

The angle of deviation of the direction of movement of the vehicle after impact (the discarding angle);

The angle between the directions of the TC movement after impact (the angle of discrepancy).

For any five established values, from these seven, a scheme of the collision process, a similar scheme shown in Fig. 6.5. At the same time, other parameters are determined.

Fig. 6.5. The relationship of vectors of the vehicle movement before and after the collision.

These values \u200b\u200bare connected with a number of others that can be determined by calculating the values \u200b\u200bof the basic parameters. To them, in particular, belong:

Relative velocity of the TC at the time of the collision (speed of the meeting);

The angle of deviating the speed of the meeting from the direction of the TC movement.

The parameters that determine the municipal location of the vehicle at the time of the collision can be assigned:

The angle between the longitudinal axes of the TC at the time of the collision (the angle of the mutual location);

The angle between the direction of the TC movement and its longitudinal axis (the corner of the drift).

In addition, the relative location of the vehicle during a collision is determined by the location on each of them the point of the initial contact.

Determining the parameters of the collision process.

Consider the relationship between the main values \u200b\u200bthat define the mechanism of the collision process. The following formulas are applicable for calculations for all types of collisions under the following conditions:

For a positive reference direction of all angles, one general direction is accepted (for example, counterclockwise);

All the angles associated with the direction of the movement of this vehicle are counted from this direction;

The angles associated with the position of the longitudinal axis of the TC are counted from the direction of the longitudinal axis. For the positive direction of the longitudinal axis, take the direction towards the front of the vehicle;

The angles that determine the mutual arrangement or movement of two vehicles are counted, respectively, from the longitudinal axis or direction of the movement of the first TC (for the first one can be taken any of the two, but equally in all calculations). The letter designations relating to the first TC are marked with a number "1", to the second EC number "2" in the lower index. The values \u200b\u200brelating to the period preceding the collision are marked by the sign "'", and by the period after the collision of the EC sign "" in the upper index. Such, for example, indicating speed and, and.

The dependences between the collision process parameters are set on the basis of the law of preserving the amount of movement, according to which the amount of system movement is constantly large and direction, if the main vector of the external forces of the system is zero. Since the external forces in the process of the collision are negligible compared to the interaction forces and they can be neglected, the vector of the equal amount of the movement of two TCs before the collision and after it remains unchanged largest and direction. The parallelograms constructed in the velocity of the Motion of the TS before the collision and after it have a general diagonal of the EC vector of the automotive vectors of the amount of TC movement at the time of the collision

\u003d +, (6.11) where, - the amount of TC movement before hit;

The amount of TC movement after impact;

The angle of the TC;

TS discarded angles.

From consideration of velocity vectors of TCs before collision, one can make another equation

\u003d, (6.12) where - the angle of deviating the speed of the meeting of the first TC from the direction of its movement (determined by the tusological methods according to the tracks remaining on it);

TC speeds before hitting.

If immediately after the impact of the vehicle is moved (jointly or separately) in one direction and at the same rate (\u003d 360є -; \u003d \u003d), then equations (6.10) and (6.11) take the following form:

=(+) ;(6.13)

After designing the vector of the amount of movement on the direction of movement after the collision, we obtain another equation

+ \u003d +. (6.15) If the vehicle moved before colliding parallel courses (\u003d 0; \u003d +), the relationship between the collision mechanism parameters is determined by the following equations:

+ \u003d +, (6.17) where is the angle between vectors and.

The above equations make it possible to obtain formulas to determine the values \u200b\u200bincluded in them. If the output of formulas is difficult, an unknown value can be determined by solving the equations after the substitution of values \u200b\u200bof known values \u200b\u200bin them.

Determination of vehicle speed before collision.

In general, when the TC before the collision was moved at an angle and after the collision were dropped in different directions at an angle, their velocity at the moment of the blow could be determined by formulas obtained from equations (6.10) and (6.11)

\u003d +; (6.19) where and - the masses of the vehicle, kg.

If before a collision, the vehicle was moving in the inhibited state, then its speed before the incident (before the start of braking) is determined by the formula

\u003d +, (6.20) where is the length of the track of the SEA until the time of the collision, m.

Example. Collision of GAZ-24 "Volga" (mass \u003d 1.5 T) and VAZ-2103 "Zhiguli" (mass \u003d 1.1 t) occurred an angle \u003d 60 ° (Fig. 6.6). The GAZ-24 car struck its front part in the middle of the left side of the VAZ-2103 car.

Fig. 6.6 DTP scheme

Before the collision, the car driver gas-24 slowed down; The trail of the JUSA to the collision site \u003d 14 m. After the collision, it has advanced in the inhibited state for another \u003d 6 m, rejected to the left of the initial direction at an angle \u003d 36 °.

Driver car VAZ braking did not apply. After the collision, this car has advanced to a distance \u003d 9.8 m with a side displacement and deviation from the initial direction by 43 ° to the right (angle \u003d 317 °).

The slowdown in both cars when moving them after a collision \u003d 5.7 m / s.

It is required to determine the speed of cars before the incident.

Decision. The gas-24 vehicle speed before the incident is determined by formula (6.20). It includes an unknown car speed at the moment of impact that can be determined by formula (6.18)

30 + 38 \u003d 36 km / h, where and - velocities of cars after impact: are determined on the basis of kinetic energy to overcome resistance when moving after impact

30 km / h;

38 km / h;

Corner sinus values: \u003d \u003d 0.407; \u003d \u003d 0.866; \u003d \u003d0,682.

Substituting in formula (6.20) the values \u200b\u200bof the magnitudes in it, we obtain

1.80,25,7+ \u003d 60 km / h;

VAZ-2103 car speed in front of the incident, we determine by formula (6.19)

Where \u003d \u003d 0.588;

There are often cases when the resistance to the movement of one of the CU during the discarding process is not allowed to be recorded (when driving outside the roadway, stops due to the strike of an obstacle, tipping). In such cases, the speed of one of the CU before the collision can be determined by solving the system of two equations with two unknown, obtained by substituting the numerical values \u200b\u200bof known values \u200b\u200bin Formula (6.18) and (6.19).

In this case, when after a collision, the vehicle was moved in one direction, the speed of one of them to the blow can be determined in two ways, depending on the data presented:

A) if the speed values \u200b\u200bare set with which the vehicle was shifted after impact, the angle of the meeting and the discarding angle of this vehicle, then its speed before the collision can be determined by the formula

\u003d; (6.21) Second TC speed before hitting

\u003d; (6.22) b) If it was not possible to establish an angle of the meeting, but the speed of the second vehicle was installed before the blow, then the speed of this TC

Example. The car GAZ-24 "Volga" (mass \u003d 1.7 tons) ran into the VAZ-2103 car (mass \u003d 1.2 tons), moving at an angle to it on the right side. After a collision, cars have advanced in one direction at a distance \u003d 6 m, deviated from the initial direction of the car-24 vehicle at an angle \u003d 28 °. On the roadway, traces of sliding of the ingenled wheels of the car GAZ-24 remained (Fig. 6.7)

Fig. 6.7. DTP scheme

The average slowdown value when moving vehicles \u003d 6 m / s.

It is required to determine the speed of cars at the time of the collision, if the car at an angle \u003d 60 ° and after the collision, advanced to the inertia stop.

Decision. Car speed GAZ-24

31.8 km / h; where - the speed of the car after impact

30.5 km / h; Corner sinus values: \u003d \u003d 0.866;

The velocity of the VAZ-2103 car is determined by formula (6.22)

40 km / h; where \u003d \u003d 0.47.

Example. Under the same circumstances of the incident, determine the speed of the gas-24 car, if it was not possible to install the direction of movement of the car VAZ-2103 before the collision, but the speed \u003d \u003d 40km / h is set.

Decision. GAZ-24 vehicle speed can be determined by formula (6.23)

where \u003d \u003d 0.88.

From the obtained two speed values, the desired can be selected based on the circumstances of the incident (see Fig. 6.7). In this case, the speed value \u003d km / h corresponds to the angle of the meeting \u003d 60 °, and \u003d km / h corresponds to \u003d 120 °.

With a longitudinal collision, the vehicle speed of one of them before the collision can be determined if the speed of another is known, according to the following formulas:

Determining the angle of the meeting in the collision

The angle of the meeting can be installed in the study of the scene in the direction of the tracks left on the road of rolling or braking before the collision. If angles are installed and the angle of the meeting is defined as their difference (Fig. 6.8).

Fig. 6.8 Parameters that determine the location of vehicles in a collision: - the angle of the meeting is the angle of the mutual arrangement at the time of the collision, the corners of the drift, the angles of deviation of the direction of movement from the longitudinal direction of the road.

For the direction of the longitudinal axis of the road, a direction is taken, in which the first TC is moving along it.

The relationship between the encounter of the meeting and the discrepancy angle is determined through the values \u200b\u200bof the discarding angles and

When moving the vehicle at the time of the collision with a drift of the meeting angle

where is the angle of the mutual location of the vehicle.

In the collision of the vehicle, moving without driving, the angle of the meeting is equal to the corner.

The angle can be determined by the deformations of the vehicle. With blocking collisions to determine the angle, it is necessary to combine the sites in contacting at the moment of impact, or (since it is not always possible) to arrange the vehicle so that the corresponding areas in contact with each other were located on the same distance from each other, if possible in the most remote places (Fig. 6.9).

It is possible to determine this angle and graphically. To do this, on the diagrams of each TC, drawn up, should be applied two points in places corresponding to the location of parts in contact with the collision. By connecting these points on the direct scheme, you need to measure the angles and between the longitudinal axes and these straight (see Fig. 6.9).

Fig. 6.9 Determination of the corner of the mutual location of vehicles at the time of the collision:

A) EC when combining vehicles;

B) EC with a separate study.

The corner of the mutual location, measured from the direction of the longitudinal axis of the first TC

If the calculation result is negative, then with a conversation collision to it should be added 180 °, and with a passing - 360 °.

The corner of the mutual location can also be determined in the directions of the tracks on the vehicle arising at the time of the initial contact in the collision. The combination of these areas in contact places allows you to establish the mutual location of the TC at the time of the collision and, therefore, the angle.

If an angle of encountering the speed of the meeting from the direction of the TS movement is set, the angle of the meeting can be determined by the formula

An angle can also be determined from equations (6.10) - (6.14). In cases where it is difficult to solve these equations in general, it follows, substituting the numerical values \u200b\u200bof all known values, bring them to the form

where, the numeric values \u200b\u200bof the coefficients obtained after the transformations carried out.

Then the angle of the meeting can be determined by the formula

Of all the values \u200b\u200bof the angle corresponding to the sine values \u200b\u200bobtained by formula (6.30), the desired is easily determined on the basis of their circumstances of the incident.

Graphic method for determining the parameters of the collision process.

Analytical method for determining collision parameters in some cases is complex. The graphic method is less complicated and more visually; Permissible errors are usually easily detected without re-examination. With a neat execution of graphic constructions, this method allows to obtain quite accurate results.

Construction of a scheme that determines the direction and speed of movement of each TC before collision and when dropping after it, it is advisable and in the study of collisions by the analytical method. It allows you to check the correctness of the calculations and can be used as an illustration that allows the investigator (Court) to make sure that the results of the study are valid.

When constructing a circuit, the vectors of the amount of movement defined by known speed values \u200b\u200bare deposited on the scale in the specified directions. The task is solved if the direction and the magnitude of the vector of the resultant amount of movement are determined. The sequence of constructing the scheme depends on what kind of data is the expert.

As an example in Fig. 6.10 The scheme is shown for the case when the directions of movement of both TCs and the speed of one of them before and after the collision. It is required to determine the speed of another TC before collision.

Fig. 6.10. Graphic determination of the parameters of the process of the collision of vehicles.

We need to solve the problem and the magnitude of the vector of the resultant amount of motion are determined by the point of intersection of direct - and - carried out from the ends of the vectors of the amount of the first TC and in parallel with the directions of the second movement.

The vector value of the vector is determined by the point of intersection with the direction of this vector direct - conducted from the end of the vector of the automatic amount of the movement parallel to the vector.

§ 5. Expert study of the process of discarding vehicles after a collision.

Regularities of throwing vehicles after a collision

The main parameters that determine this stage of the collision mechanism are the directions of the TC movement after impact (reference direction), the trajectories of their inertia movement to the place of stopping and sweeping speed.

Under the influence of the impact impulse in a collision, by the time of the completion of deformations, the mass centers of colliding TCs change the speed and direction of movement. Immediately after the collision, the center of mass MAS TC moves almost straightly in the direction of acquired speed. In the process of further inertia, the speed changes due to resistance to movement. The direction of movement may vary.

When the inertia is moved to the inertia of the non-rotated vehicle at some angle to the plane of rotation of the wheels, the direction of its movement gradually changes. Under the influence of transverse components of the horizontal reaction forces of the road arising from the movement at an angle to the plane of rotation of the wheels, the trajectory of the center of the center of mass vehicles occurs.

Slow down when tap discard, and consequently, the distance to which it is discarded at a given speed is determined by the resistance coefficient

If the vehicle is moving in the inhibited state or in the direction close to the wheel rotation perpendicular to the plane, then the coefficient of resistance to the movement

where is the transverse clutch coefficient with the road;

The angle of the roadway in the direction of movement of the vehicle.

When the vehicle with a damaged chassis, the coefficient depends on the nature of the interaction of damaged parts with the road and with sufficient accuracy can only be installed experimentally.

In cases where after a collision, the TC is discarded in an uneasable state, the coefficient depends on which angle to the rotation plane moves. When discarding in the direction close to the direction of the longitudinal axis of the vehicle, the coefficient is close to the value of the coefficient of rolling resistance, during discarding in the direction close to the transverse one.

Determination of the sweep rate

The method of calculating the rate of discard depends on the conditions of the TC movement after impact. If after a collision moved with a constant slowdown, then the rate of discarding

where is the movement of the center of mass CU from the place of collision to the place of stop, m.

When crossing the vehicles of sections with different resistance to movement, the discard rate can be determined by the formula

where, - movement of the center of gravity of the mass of the vehicle between the boundaries of the sections with different resistance to the movement, m;

Slowing TC in these areas, m / s.

§ 6 Determination of the collision of vehicles

Initial data to establish a collision location

The ability to solve the issue of the collision of the TC by expert path and the accuracy with which the location of each TC can be established on the road at the time of the collision, depend on what initial data is about the circumstances of the incident, the expert has and how accurately they are installed.

To establish or clarify the location of the vehicle at the time of their collision, the expert requires such objective data:

About traces, collisions of the vehicle at the scene of the incident, about their character, location, length;

On the tracks (tracks) left by the objects discarded in a collision: parts of the vehicle, separated when hitting the cargo, etc.;

On the location of the sections of the accumulation of small particles separated from the velocity: fallen earth, dirt, glass fragments, splashing areas of liquids;

On the location after the collision of the vehicle and objects discarded during the collision;

On damage to the vehicle.

In most cases, the expert has only some of the listed data.

It should be noted that as if in good faith, the situation at the scene by persons who do not have experience in the production of autotechnical expertise (or unfamiliar with the methodology of expert research) are inevitable to omissions that are often the reason for the impossibility of establishing a collision location. Therefore, it is very important that the inspection of the scene was made with the participation of a specialist.

In view of the inspection and exploration of the scene, first of all, it is necessary to record those signs of incidents, which during the inspection may change, for example, traces of braking or drift on wet coverage, traces of movement of small objects, traces of tires remaining when crossing puddles or leaving Earth during the rain. You should also lock the location of the vehicle, if you need to move them to assist victims or to release the roadway.

Determining the place of collision in the footsteps of vehicles.

The main features for which the collision can be determined is:

Sharp deviation of the track of the wheels from the initial direction arising from eccentric impact on the vehicle or when the front wheel is impact;

Transverse trace displacement arising from the central impact and the constant position of the front wheels. With a minor transverse displacement of a trace or insignificant deviation, these signs can be found by considering the trace in the longitudinal direction with a low height;

Traces of the side shift of uncloned wheel arising at the time of collision as a result of the transverse bias of the vehicle or the sharp turn of the front wheels. As a rule, such traces are minor;

Termination or rupture of the track. Occurs at the time of collision as a result of a sharp increase in the load and disruption of the wheel blocking or wheel separation from the surface of the road;

The trail of the Single Wheel, according to which a blow was defeated, which joined it (sometimes only for a short period of time). At the same time, it is necessary to take into account, in which direction the trace is formed on the basis of the location of the vehicle after the incident;

Traces of friction of parts of the vehicle on the coating during the destruction of its running part (when the wheels are separated, the destruction of the suspension). Start usually at the collision;

Traces of moving both vehicles. The collision location is determined at the place of crossing the directions of these traces, taking into account the mutual location of the vehicle at the time of the collision and location on them, leaving traces on the road.

In most cases, the listed features are minorly, and when an inspection of the scene is often not fixed (or they are not fixed enough). Therefore, in cases where the establishment of the exact location of the collision location is essential for the case, it is necessary to conduct an expert study of the scene of the incident.

Determination of the collision site on the tracks left by the discarded objects

In some cases, the place of collision can be established in the direction of the tracks left on the road with objects discarded during the collision. Such tracks can be scratches and consistently located potholes on the road left by parts of the vehicle, fallen motorcycles, bicycles or cargo, as well as traces of drawing of drivers or passengers who dropped out of the CU at the moment of impact. In addition, there are traces of moving small objects, visible on snow, soil, dirt, dust.

Initially, the discarded objects move straightly from the place of their separation from the vehicle. Then, depending on the configuration of the object and the nature of its movement along the surface of the road, a deviation may be deviated from the initial direction of movement. With a clean slide, the movement of objects remains almost straightforward to the stop. When moving in the process of moving, the direction of movement as the speed decreases it can change. Therefore, the place of collision of the TC can be installed on the traces left by the ledmed objects in cases where there are signs that these objects moved straightforwardly or the trajectory of their movement is viewed throughout.

To determine the location of the vehicle at the time of collisions in the footsteps left by the discarded objects, in the direction of the intended place of the collision should be carried out by the continuation of these traces. The location of the intersection of these lines will determine the place of impact (the place of separation from the TC objects left traces).

The larger the traces left by the discarded objects, the more accurate the collision can be set, because it is possible to choose the most informative traces, excluding those of them that could deviate from the direction to the place of collision (for example, when rolling out of their objects, the movement of objects through irregularities , location of the start of the footprint at a high distance from the collision site).

Determination of a clash site for the location of objects distinguished from vehicles.

It is not possible to determine the place of collision of the vehicle in the location of individual parts, since their movement from the velocity depends on many factors that cannot be taken into account. The portion of the location of the greatest number of parts discarded when a collision can only be approximately indicated in the collision place. Moreover, if the place of collision is determined by the width of the road, all circumstances that contributed to one-sided displacement of the discarded parts in the transverse direction should be taken into account.

A fairly accurate place of the collision is determined by the location of the Earth, creepy from the lower parts of the vehicle at the moment of impact. In the collision, the particles of the Earth are discarded with a greater speed and fall on the road almost in the place where the blow took place. The greatest amount of land is separated from the deformable parts (surfaces of the wings, mudguards, the bottom of the body), but with severely pollution of the car, the land may turn from other sites. Therefore, it is important to establish, not only from which TC is lit up, but also from which parts. This will make it possible to more accurately set the place of collision. At the same time, the boundaries of the sedimentation areas of the smallest particles of the Earth and dust should be taken into account, since large can shift from the inertia fall.

The establishment of the vehicle, from which the land was tremended in this area, in many cases it is easy, since the contamination of the lower parts of different vehicles is usually sharply varied by quantity, and in appearance. However, in doubtful cases, there may be a need for chemical research.

The collision may also be determined by the location of the separation of fragments. At the moment of strike, the fragments of glasses and plastic parts are scattered in different directions. With sufficient accuracy, the influence of all factors for the movement of fragments is difficult, so it is possible to determine the place of impact only by the location of the dispersion site (especially in its various sizes) is only approximately.

In determining the place of collision by the location of the fragments in the longitudinal direction, it should be borne in mind that the fragments in the direction of movement of the vehicle are scattered in the form of an ellipse, the nearest boundary of which is located on the place of impact at a distance close to the magnitude of their movement in the longitudinal direction during the free fall. This distance can be determined by the formula

where - the speed of the vehicle at the time of the destruction of the glass, km / h;

Height of the location of the bottom of the destroyed glass, m.

As a rule, the smallest fragments are located closest to the place of impact, large can move much further, moving along the surface of the road after falling by inertia.

More precisely by the location of small fragments, the place of collision is determined on the wet, dirty, dirt road or on the road with a rubbed coating, when slipping of small fragments on the surface of the road is difficult.

With oncoming collisions, the place of impact in the longitudinal direction can be approximately determined on the basis of the location of the far boundaries of the areas of scattering of glass fragments, discarded from each of the collided TCs in the direction of its movement. With a similar nature of the destruction of the same type of glasses, the maximum range of rolls of fragments during their movement along the surface of the road is directly proportional to the squares of velocity velocities at the time of collision. Therefore, the place of collision will be from far the boundaries of the scattering section of the first TC glass fragments at a distance

where - the full distance between the long-distance boundaries of the separation of shards of the glasses of opposite TCs (Fig. 11).

Fig. 6.11. Determination of the place of collision for the distance of the separation of shards of glasses

Determining the far boundaries of the scattering areas of the glass fragments, it should be excluded the possibility of an ERC error to take for those discarded those fragments that are treated with the progress of it after a collision.

In the width of the road, the collision location can be approximately determined in cases where the dispersion site has a small width and can be installed the direction of the longitudinal axis of the dispersion ellipse. It should be borne in mind the possible error in cases where the dispersion of fragments to the right and left to the direction of movement of the vehicle was unequal (for example, as a result of ricochetizing fragments from the surface of another TC).

Determination of the collision location of vehicles

The direction of movement and the location on which the CU moves from the collision location, depend on many circumstances of EC from the speed and direction of the TC movement, their masses, the nature of the interaction of contacting parts, resistance to movement, etc. Therefore, the analytical dependence of the collision location coordinates from the values \u200b\u200bdetermining these circumstances In general, it is very complex. The substitution in the estimated formulas, even with small errors, can lead an expert to erroneous conclusions. Install the values \u200b\u200bof these values \u200b\u200bwith the necessary accuracy is almost impossible. Therefore, on the basis of data on the location of the vehicle after the incident, the collision may be determined only in some particular cases.

When conducting experts on road traffic accidents, the question of which side of the roadway occurred the collision of the vehicle moving by parallel courses.

To solve this issue, it is necessary to accurately establish a cross offset of the CU from the collision site, which, in the absence of data on the tracks remaining on the road, can be established by the location of the vehicle after the incident.

The most accurate place of collision is determined in cases where the TC after a collision remains in contact with each other (or diverge to a slight distance). The transverse displacement of the CU from the collision site occurs then as a result of their turn on the total center of gravity. The movement of the vehicle is approximately inversely proportional to the masses (or gravity forces), therefore, to determine the transverse displacement from the collision location, you can use the following formula (Fig. 6.12):

where - the distance between the centers of the TC after the incident (finite), measured in the transverse direction, m;

The distance between the centers of gravity TS at the time of the collision, measured in the transverse direction, m;

TC masses, kg.

Fig. 6.12. Offset vehicles in a collision:

I - the position of the TC at the time of the collision;

II EC TC position after a collision.

If collided TCs are shifted in transverse to the road axis, this offset can be determined based on the condition of equality of projections of the vectors of the movement of both TCs on the transverse direction. Since the exact value of the casting angles in such cases is unknown, the transverse displacement of them with sufficient accuracy can be determined if there are signs that the discarding angles of both TCs are close to their value or discarding occurred in the direction close to the transverse one. Depending on the required accuracy of the calculation of the sinus of the discard angle can be accepted equal to one (SIN80 ° \u003d 0.985, SIN70 ° \u003d 0.940, SIN60 ° \u003d 0.866).

Then the total transverse offset of the CU from the collision site can be determined by the formula

where - the distance between the centers of gravity of the TC at the time of their contact, measured in the transverse direction, m;

The average value of the TC slowdown in the sections of their discarding after the collision, M / SI.

Based on the above calculations, the output of the expert can be formulated in categorical form, provided that it does not change with all possible deviations of the values \u200b\u200bof the values \u200b\u200bof the values \u200b\u200bincluded in the formulas.

The conclusion that the TC is greater mass was on its side of the roadway, it can be done when calculating at the maximum possible value in a particular case (taking into account the nature of the deformations and the possible value of the angle, the discarding. In the opposite output, the value should be taken equal to the opposite output (or The minimum possible).

Example. On the section of the road, divided into two bands with a solid line of longitudinal markup, there was a collision of the car ZIL-130 (mass \u003d 9.5t) with a gas-24 Volga car (mass \u003d 1.7Т), which followed in the counter direction by parallel course. Cars have collided by the left side of the front parts with the overlap \u003d 0.75m.

After the collision, the cars turned in the transverse direction, remaining in contact with each other (Fig.6.13). The distance between their centers of gravity in the transverse direction \u003d 4.7m; Distance from the center of gravity of the car ZIL-130 to the line of longitudinal markup 2m.

Fig. 6.13. Offset by vehicles in the collision of cars ZIL-130 and GAZ-24 "Volga"

The creaked earth was under the right side of the front of the car ZIL-130 on both sides of the longitudinal markup line.

It is required to install, on which side of the roadway the road there was a collision.

Decision. The distance to which the center of gravity of the car ZIL-130 in the transverse direction in the collision was shown according to formula (6.37)

\u003d \u003d (4.7-1.4). \u003d 0.5 m,

0.75 \u003d 1.4 m;

The overall width of the car ZIL-130 EC 2.5M;

The overall width of the car GAZ-24 -1.8M.

At the time of collision, the ZIL-130 car was on his side of the roadway. Its left side was removed from the axial line about 0.25m (see Fig.6.13).

Clarification of the clash site for vehicle deformations

The study of damage obtained by the vehicle during a collision often allows you to set the mutual arrangement of them at the time of the collision and the direction of impact. So, if the direction of movement is determined and the location of one of the collided TCs at the moment of impact, then the location of the other TS and the point in which their primary contact occurred on damage. In many cases, this allows you to determine which side of the road part of the road there was a collision.

If only the location of the vehicle after the incident is known, then the damage can be installed the impact direction and the likely shift of the TC after impact. The most accurate place of collision can be determined if the distance to which the vehicle was shifted after the strike is insignificant.

In collisions that are the result of a sudden turn to the left of one of the colliding TCs, the extreme right position of this TC is determined at the time of the collision based on the possibility of maneuver under the clutch conditions. In some cases, this allows you to establish on which side the collision occurred if it was determined by deformations, at what angle a blow was applied.

§ 7. Technical opportunity to prevent collision

Approach to solving the issue.

The question of the availability of the driver of the technical ability to prevent a collision is important to assess its actions before the incident and establish a causal connection with the consequences. The general approach to its solution is to establish whether the driver managed to perform the necessary actions that excluded the collision when an objective possibility arose to detect the risk of collision.

The driver who enjoys the advantageous right to move should take measures to prevent accidents from the moment when it has the opportunity to find that another TC by the time of rapprochement will be on the vehicle driven by it.

When cross collisions, this moment occurs when the driver has the opportunity to detect another TC at such a distance from the place (where it should have stopped to give way to the road), on which his driver can no longer do this driver (i.e. When the other TC approached this place at a distance equal to the way of braking).

At counter collisions, the specified point occurs when the counter TC turns out to be a distance of this vehicle at a distance that no longer allows its driver to give way to the road, or when the driver has the opportunity to estimate the road environment in which the oncoming vehicle may be on the strip of its movement (for example , due to the drift and reversal, created for this vehicle of the road situation, etc.).

With associated collisions, such a moment occurs when the driver has the opportunity to find that another vehicle begins to deviate in a dangerous direction and by the time of rapprochement with it will be on the lane of the vehicle managed by them.

Technical ability to prevent cross-collisions

The question of the technical capabilities of the driver to prevent cross-collision can be resolved by making a distance from which the driver could still give an opportunity to cross the road to go beyond the danger zone, with a distance that allows him to detect the risk of collision.

Distance can be determined by the formula

where - the time required by the driver to bring the brakes into action, with;

An extra time required for the other TC to get out of the danger zone, C;

Time of complete braking to stop, with:

The time of movement of the inverted vehicle before the collision, with:

The full path of braking TS, M;

The path of braking of this vehicle before collision, m;

Length of the trace of JUSA left before the collision, m.

In cases where the collision occurred before braking, formula (6.39) is simplified. Substituting in this formula value \u003d 0 and \u003d 0, we get.

The value is determined depending on how the distance would additionally be moved to another TCs so that the collision is expelled.

If another TS collision moved in the inverted state, then the value can be determined by the formula

If the other TC before the collision was moving without braking, then the time is determined by the formula

If another exceeds the distance from which the driver should take action to brake, then it can be concluded that he had a technical ability to prevent a collision.

If the blow has been applied to the front of the first TC on the side of the second side, then the value is equal to which the TC would be additionally advanced to the exit beyond the limits of the first strip.

If the blow was applied to the front of the second TS and both TCs were moving in the inhibited state before the collision, then the value can be determined from the equation (Fig. 6.14)

where is the overall width of the first TS, m;

The overall length of the second TS, m;

The distance that came to the time of the collision of the front part of the first TS for the near border of the second, m movement, m;

The average speed of the first TC in the area;

The average speed of the second vehicle in the site; It is expressed by a formula, similar to (6.44).

Fig. 6.14. The cross-collision circuit of vehicles:

I EC Position of the TC at the time of the collision;

II EC TC position at the time of reaching the first strip

Second movement;

III EC, the position of the second TC, excluding the collision.

Since the solution of equation (6.43) is generally cumbersome, it is advisable to first substitute the numerical values \u200b\u200bof all the values \u200b\u200bincluded in it, and then solve the resulting equation relatively.

If before the collision, another vehicle was moving without braking, then the value can be determined by the formula obtained from equation (6.43)

Example. To determine how much the distance was supposed to advance the car GAZ-24 "Volga", which followed at a speed \u003d 60 km / h, so that by the time of the strip of his movement, the car ZIL-130 was excluded. The car ZIL-130, which followed at a speed \u003d 50 km / h, left before the collision left the braking \u003d 6m to the rear wheels. Slow down when braking \u003d 5.8 m / s.

The blow during the collision was applied to the front of the GAZ-24 car on the right side of the ZIL-130 car at a distance \u003d 3m from its front to the rear border of damage.

Decision. The desired value is determined by the formula (6.45)

13 m,

where is the average velocity of the car ZIL-130 in the area \u003d 3m; Specified by formula (6.44)

30.6 km / h,

Movement path of the car ZIL-130 to the stop:

16.6 m;.

The path of braking car ZIL-130 before the collision:

Technical ability to prevent a counter-collision

In cases where the oncoming TCs were slow down to the moment of the collision, the question of the technical capabilities of the driver to prevent collision by braking does not make sense, since neither the reduction in speed, nor the stops exclude the possibility of a collision. The question can be delivered only to what the velocity of the TC could occur if the driver slowed down in a timely manner; The expert's response to this question may be important when establishing a causal relationship between the actions of the driver and the consequences.

If the oncoming vehicle was moving before the collision in the inhibited state, the question of the technical capabilities of the driver of this vehicle prevented a collision can be resolved. To do this, locate both TCs at the moment when the driver of this vehicle still had the technical opportunity to stop, not reaching the place where the accelerated head vehicle should have stopped (if his movement was not detained during a collision), and evaluate the created in This moment is a road atmosphere. If she has already represented a danger to movement, then it should be concluded that the driver has a technical ability to prevent a collision.

The location of this (first) TC at the time when the driver still had a technical opportunity to prevent a collision, determined by the distance to the collision site. This distance is equal to the sum of the stopping path and the distance to which it would be advanced after the collision's place the inhibited oncoming (second) vehicle, if his movement was not detained in a collision

where is the speed of the second TC in a collision, km / h;

Second TC speed before braking, km / h;

The distance that has overcome the second TS in the inverted state before the collision, m.

The location of the oncoming TC at that moment (when the driver of the first TS still had the technical ability to prevent collision by braking) is determined by the distance from it to the collision place

where - the time of overcoming the first vehicle of the distance taking into account its braking in a plot equal to;

The distance that is overcome the first TC in the inverted state to collision, m;

The movement time of the first TC in the inhibited state before the collision, C;

The time of movement of the second TC in the inverted state before the collision, C;

The speed of the first TC before the start of braking, km / h.

If at the time when the distance between the vehicle was equal to the amount +, the driver of the first TS could evaluate the road situation as a dangerous one, it should be concluded about the values \u200b\u200bof his technical ability to prevent a collision.

Example. When you try to avoid a collision with the next car, the driver of which sharply slowed down, the driver of the car ZIL-130 drove on the left side of the road, where the collision was collided with the GAZ-24 Volga.

In front of the incident, the car ZIL-130 followed at speed \u003d 60km / h, the car GAZ-24 EC at speed \u003d 80 km / h.

At the scene there were traces of UNUSA. Until the rear tires of the car ZIL-130, ZIL-130 traces of 16 m long, the rear tires of the GAZ-24 EC car with a length of 22 m. Slow down when driving in the inverted state was \u003d 4 m / s.

Whether the technical opportunity has a car-24 car driver to prevent a collision if at the time of the start of the car of ZIL-130 on the left side of the road the distance between these cars was about 100 m.

Decision. The distance between cars at the time when the GAZ-24 driver also had a technical ability to prevent a collision, is defined as the amount of distances at this point from each of them to the collision site.

Distance from GAZ-24 car to collision site at the specified point (Formula 6.46)

85 + 15 \u003d 100 m,

where - the stopping path of the GAZ-24 car is equal at a speed of 80 km / h 85 m;

The distance to which the ingenled car ZIL-130 would have come from the place where the collision occurred if it was not detained by the blow:

Moving the car ZIL-130 from the moment of the start of efficient braking before the collision;

19.3 m,

Moving the car ZIL-130 moment of the beginning of the formation of traces of the JUSA to a collision, equal to 16 m;

Time of deceleration time when braking the car ZIL-130, equal to 0.4 s.

The distance from the car ZIL-130 to the place of collision at the time when the car driver of GAZ-24 has also had a technical opportunity to prevent collision (Formula 6.49)

\u003d + \u003d (4,65-1.4) + 19.3 \u003d 73 m,

where is the time to overcome the gas-24 distances;

1,17 \u003d 4.65 s;

Moving a gas-24 car from the moment of braking before collision;

Moving the GAZ-24 car from the moment of the formation of traces of the JUSA before the collision, equal to 22 m;

GAZ-24 car deceleration growth time, equal to 0.1 s;

Time of movement of the inhibited car GAZ-24 before the collision (Formula 6.3)

1.17 s;

The time of movement of the inhibited car ZIL-130 before the collision (Formula 6.3)

As the calculations are shown, the driver of the gas-24 car could prevent collision by braking, when the distance between cars was less than + \u003d 100 + 73 \u003d 173 m. But at this time, the ZIL-130 car was still moving along his side of the roadway and the danger to The movement of the car GAZ-24 was absent.

When ZIL-130 began to leave on the side of the roadway, the distance between cars (100m) was already insufficient for the timely stop of the GAZ-24 car. Consequently, his driver did not have a technical opportunity to prevent a collision.

Technical ability to prevent a passing collision

The question of the technical ability to prevent a collision with a passing vehicle arises, for example, in cases where the vehicle moving at a lower rate, suddenly leaves the lane of the movement of this vehicle (during rebuilding from the adjacent strip of movement, when traveling from a secondary road to the main road) . If the collision is the result of a sudden braking of the transmitted TC, then the assessment of the actions of the TC driver, which followed the rear, should be made only in terms of the correctness of the choice of the distance. If the distance was elected correctly, then it is obvious that the driver has an opportunity to prevent a collision.

The complexity of solving the issue of technical ability to prevent a collision during a passing movement is related to the difficulty of establishing the distance between the TC at the time when the rear TC driver had the opportunity to detect a danger to movement. Such data set by the investigative way is usually contradictory.

If the distances between the TS are installed at the time of the danger and the speed of their movement, the question of the technical ability to prevent collision is solved by comparing this distance with a distance that would be sufficient to ensure that during timely braking (based on the installed driver reaction time) TC Did not come in contact with each other.

This distance can be determined by the formula obtained under the condition that by the time of the rapprochement of the TCs of their speed is balanced

where - the difference in the speeds of colliding the vehicle before the incident, km / h;

The time required by the driver to bring the brakes into action.