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Problems of modelling a pedestrian collision – selected aspects

Aleksandrowicz Piotr, Wrona Rafał, Droździel Paweł

Advances in Science and Technology. Research Journal

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2025

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Vol. 19, no. 7

44--55

EN

The article studies modelling a collision of a pedestrian with a car and the components of road infrastructure. With the study of the course of the road accident, there are analysed the possibilities of using a human body multi-solid model and the kinematic model for impact parameters reconstruction. The study also considers the possibilities of applying an analytic approach and road incidents databases, supplementary to computer simulation, offered by today’s programs used in road accident reconstruction. The study results demonstrate an application potential, and they can be used for road traffic safety enhancement. The effects of collisions with unprotected road traffic participants are most tragic and very expensive, hence considering the problem is this article is very important also for socioeconomic reasons.

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On a possibility of complicating the mathematical model of a collision between two motor vehicles

Aleksandrowicz Piotr, Zalewski Jarosław

Advances in Science and Technology. Research Journal

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2025

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Vol. 19, no. 3

63--73

EN

In this paper a survey on some selected problems of motor vehicle collisions modeling has been undertaken. The aim of this paper was to replace the classic approach basing on a planar motion with a more complex resultant motion to examine the potential additional factors affecting the process of a collision. In case of a collision between two vehicles, especially for a large velocity, the colliding vehicles may break away from the road surface and perform a motion that requires including some more sophisticated approach to understand a road collision process, particularly in view of its short time duration. Moreover, the most common frontal or rear collision model has been replaced with the side impact collision model in which one vehicle struck the side of the other. Such approach makes the collision model even more complex. Of course it was also necessary to undertake other phenomena as well. Apart from adopting a simple momentum – impulse collision model the authors took into account the friction between the bodies of the vehicles involved in a collision in order to analyze the possibility of the coefficient of restitution in case of both normal and tangential direction versus the plane of collision common for both vehicles. In case of a resultant motion during the collision the forces of inertia, transportation and Coriolis were included. Such analysis can be a tool to better understand the crucial parameters of any collision between motor vehicles rather than perform a forensic expertise. The novelty and one of the most important results of this paper may be creation of the more complex mathematical model of a collision between two vehicles when compared to the regular models. Such model can include the factors, such as the resultant motion during a collision, that enable providing more realistic description of a collision process than in a typical scenario. Of course, the paper deals with the momentary phenomena, which last for a very short period of time (e.g. 0.1s), hence including the factors which make the collision model more complex may allow understanding its course and, what is more, the potential effect on the post-collision motion of the vehicles involved.

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Selected problems in a vehicle-to-truck collision modeling

Zalewski Jarosław, Aleksandrowicz Iwo, Aleksandrowicz Piotr

Transport Problems

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2024

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T. 19, z. 1

199--208

EN

A selected case of a frontal, eccentric and oblique road vehicle-to-truck collision has been analyzed here as an example of the potential resultant motion by the motor vehicle with the truck performing a planar motion. This case is a pure problem of collision mechanics, so the main aim of the case presented here was to identify the selected parameters of such a collision with the three components of the collision impulse of only one vehicle taking part in it. The problem was analyzed with the use of a computer simulation performed in a software called V-SIM which is quite popular as a tool for accident reconstruction by e.g., forensic experts and others associated with road safety, especially in Poland. The results of all simulations were important in providing the basics of mathematical modeling regarding collision mechanics. The obtained observations may further be used for a dedicated software, should such be created. Not only a normal and a tangential but also a bi-normal direction versus the adopted plane of collision was considered.

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Problem with determining the vehicle impact velocity for car bodies breaking apart

Aleksandrowicz Piotr, Aleksandrowicz Iwo, Kukiełka Krzysztof, Patyk Radosław, Stanowski Piotr

Transport Problems

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2022

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T. 17, z. 3

75--86

EN

This article investigates the impact of a passenger car on a tree, which resulted in the car body breaking apart. A side impact of the car on a tree at high driving speeds is not a standard test in the provisions of the applicable Directives of the European Economic Community, even though the impact poses a serious threat to the driver and the passengers. The threat comes from a deep impaction of the barrier into the body which damages the safety cage. For such impacts, it is very difficult for the vehicle speed to be reconstructed. In practice, expert witnesses and appraisers usually disregard the bodybreaking-apart-related energy due to a difficulty in establishing the data for such calculations, which leads to simplifications and speed underestimates. Performing the right simulation of such impacts with accident reconstruction programs without determining the adequate input data for calculations is also impossible to calculate. This paper presents a range of studies and calculations for such incidents and for identifying the input parameters for collision simulations. The approach presented in this article should be used by expert witnesses and researchers. Therefore, this paper provides insights into theory and practice.

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Verification of motor vehicle post accident insurance claims

Aleksandrowicz Piotr

Transport Problems

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2020

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T. 15, z. 1

25--38

EN

Use of a vehicle involves a risk of collision and, consequently, high costs of post-accident repairs. Therefore, if there is no insurance cover and the repair must be paid by the vehicle owner, some of them choose to file fraudulent insurance claims as the damage can be very difficult to verify. Payments of undue damages pose a major social and economic problem. This article deals with these problems and puts forward a proposition of insurance claim verification by means of a new research method to increase the efficiency of detection and elimination of such claims. This new method requires division of the damage-verification process into static analysis (S), dynamic analysis (D) and analysis of characteristic damage (C). The obtained results show that insurance companies have had problems with selection of appropriate research methods to verify the insurance claims. Application of the proposed new method allows to reduce payments of undue damages and the costs of court proceedings.

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Collision model simplifications in the dynamic analysis with the SDC method

Aleksandrowicz Piotr

Transport Problems

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2020

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T. 15, z. 2

35--44

EN

The number of motor vehicles in the European Union (EU) is constantly increasing, which is causing an increase in the traffic volume. This, in turn, boosts the economic development of the EU member states. However, an increase in traffic volume leads to road collisions and accidents, which lead to high repair costs. Some accident victims report fake vehicle damage to extort money for repairs. There are criminal groups that stage accidents for this purpose; thus, these claims are very difficult to verify. Thus, it is not enough to verify the sustained damage only by comparing the geometric parameters of the impact traces. New, modern research methods with simulation programs need to be used in order to reconstruct the course of an accident. The SDC (Static Dynamic Characteristic method) provides the possibility of vehicle damage verification, according to this convention. However, simplified modelling with the use of simulation programs involves the necessity of identification of input parameters in order to reconstruct a collision and the vehicle’s post- collision movement. If the input parameters are not correct, the simulation results will also be incorrect, which will have a direct impact on the parties involved in potential legal proceedings, both civil and criminal. This study deals with the identification of the impact parameters and sensitivity of the simulation results to input data. Impact verification with the SDC method shows both a knowledge enhancement and a practical value. They can be used by experts, expert witnesses, computer programmers, researchers and students.

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Identification of the parameters of a vehicle crashing into a round pillar

Kostek Robert, Aleksandrowicz Piotr

Journal of Theoretical and Applied Mechanics

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2020

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Vol. 58 nr 1

233--245

EN

This article presents a study on reconstruction of a crash of a passenger car – Opel Mokka, into a pillar. Computer simulations were performed with software V-SIM4, both for default data and data identified from the crash test. The crash test was performed by AUTOBILD and DEKRA. The frontal collision with a pillar is not a standard crash test recommended by the Directives of Communaut´e ´Economique Europ´eenne (CEE), even though this type of collision poses a serious threat to the safety of vehicle users. The threat comes from the large penetration of the vehicle body through the pillar. These accidents are difficult to reconstruct with the programs applied by expert witnesses, because they require a lot of experience and changes in many parameters. Identification of these parameters is critical in this case. Values of the parameters were identified from recorded images. The obtained results of simulation show strong sensitivity of the accident course to the position of the force application point, which acts between the pillar and the vehicle. Also, the key factors are: contact parameters, identification of the initial conditions, sensitivity of the course of the accident to the adopted values of the parameters, and knowledge of the limitations of any software. Many expert witnesses do not even realise that their results of simulations, based on default values, are faulty. The process of obtaining an agreement between the simulation and experimental results is a time-consuming iteration process. This process is described in this article, which is address to expert witnesses and researchers; moreover, a direction for development of software was suggested.