[Automobile versus pedestrian accidents analysis by fixed-parameters computer simulation].

OBJECTIVE: Using computer simulation to analyze the effects of speed, type of automobile and impacted position on crash-course and injuries of pedestrians in automobile vs. pedestrian accidents. METHODS: Automobiles (bus, minibus, car and truck) and pedestrian models were constructed with multi-body dynamics computing method. The crashes were simulated at different impact speeds (20, 30, 40, 50 and 60 km/h) and different positions (front, lateral and rear of pedestrians). Crash-courses and their biomechanical responses were studied. RESULTS: If the type of automobile and impact position were the same, the crash-courses were similar (impact speed < or = 60 km/h). There were some characteristics in the head acceleration, upper neck axial force and leg axial force. CONCLUSION: Multi-body dynamics computer simulation of crash can be applied to analyze crash-course and injuries (head, neck and leg) of pedestrians.

Study of injuries combining computer simulation in motorcycle-car collision accidents.

This paper presents the approach of computer simulation to clarify the questions faced by forensic experts about what causes the various injuries characteristic of two motorcycle victims, including the motorcycle driver and the back seat occupant on the motorcycle, and how to exactly confirm which one of them is the motorcycle driver. Two typical motorcycle-car accident cases were reconstructed to analyze the movement and the load of both the motorcycle driver and the back seat occupant in the collision course. In case one, the back seat occupant suffered fatal head injuries when he fell on the ground after being thrown higher than the motorcycle driver over the top of the car. In case two, the compressive force loaded by the right tibia of the back seat occupant was larger and more durative compared with the motorcycle driver; the back seat occupant suffered a bursting fracture injury of his right tibia. These results might be useful for forensic experts in dealing with similar motorcycle-car collision accidents in the future.

[The characteristics of computer simulation of traffic accidents].

OBJECTIVE: To reconstruct the collision process of traffic accident and the injury mode of the victim by computer simulation technology in forensic assessment of traffic accident. METHODS: Forty actual accidents were reconstructed by stimulation software and high performance computer based on analysis of the trace evidences at the scene, damage of the vehicles and injury of the victims, with 2 cases discussed in details. RESULTS: The reconstruction correlated very well in 28 cases, well in 9 cases, and suboptimal in 3 cases with the above parameters. Accurate reconstruction of the accident would be helpful for assessment of the injury mechanism of the victims. CONCLUSION: Reconstruction of the collision process of traffic accident and the injury mechanism of the victim by computer simulation is useful in traffic accident assessment.

[Simulation study on the bicyclist involved traffic accident and analysis of the injury].

OBJECTIVE: This study aimed at computer simulation of reconstruction of vehicle-bicyclist traffic accidents and investigation of the injury characteristics. METHODS: To use the model established by high performance computer and PC-Crash software to study the bicyclists and vehicles and to reconstruct the accident. RESULTS: The model of computer simulation response perfectly reconstructed phases of the traffic collision and explained the mechanisms of the injuries of the bicyclists, which correlated with details found in forensic investigation. CONCLUSION: Computer simulation is feasible for forensic analysis on the injury mechanism of bicyclists in traffic related accidents.

[Characteristics and biomechanical mechanism of riding injuries in accidents of bicycles collided by motor vehicles].

OBJECTIVE: To study the characteristics and biomechanical mechanism of riding injuries involving bicycles collided by motor vehicles. METHODS: The real traffic accident cases of bicycles collided by motor vehicles, including the information of scenes, bicycles, motor vehicles, rider wounds and traffic directions, were collected. Retrospective method was used to study these riding injuries. In addition, typical cases were selected to simulate traffic accident courses with computer simulation software, and the dynamic data like acceleration, force, moment were cxtracted to compare with those in the real cases. RESULTS: There were no difference of occurring frequency between cases with or without riding injuries, as well as between one-side-collision and front- or back-collision. The riding injuries seemed less in accidents involving large-scale vehicles. The frequency of riding injuries increased with vehicle speed. The wound location was low on collision side and high on opposite. CONCLUSION: Analysis of riding injury characteristic in traffic accidents and their biomechanical mechanism would be helpful for estimation of traffic manner.

[Computer simulation by passenger wound analysis of vehicle collision].

OBJECTIVE: To reconstruct the course of vehicle collision, so that to provide the reference for forensic identification and disposal of traffic accidents. METHODS: Through analyzing evidences left both on passengers and vehicles, technique of momentum impulse combined with multi-dynamics was applied to simulate the motion and injury of passengers as well as the track of vehicles. RESULTS: Model of computer stimulation perfectly reconstructed phases of the traffic collision, which coincide with details found by forensic investigation. CONCLUSION: Computer stimulation is helpful and feasible for forensic identification in traffic accidents.