The Collision and Trajectory Models of PC-CRASH

TLDR

The paper presents the trajectory and collision models that underpin the PC‑CRASH accident reconstruction program. PC‑CRASH is a Windows-based program that simulates pre‑collision, collision, and post‑collision dynamics for multiple vehicles using a discrete‑kinetic forward simulation of 3D kinematics, incorporating tire‑force, steering, braking, weight shift, suspension effects, and a momentum‑based collision model that relies on restitution, while also handling secondary impacts, inter‑vehicle friction, and vertical impulse vectors. The authors demonstrate the models and PC‑CRASH’s built‑in 3D animation through a simple reconstruction example. Conference abstract reference: IRRD 898597.

Abstract

PC-CRASH is a Windows-based accident reconstruction program which combines the simulation of pre-collision, collision, and post-collision dynamics for multiple vehicles in a graphical environment. This paper presents the trajectory and collision models on which PC-CRASH is based. PC-CRASH's model for predicting the three-dimensional (3D) kinematics of a vehicle's pre- and post-impact trajectory is based on a discrete-kinetic time forward simulation. The tire-force model, steer angle, wheel braking, weight shift, and suspension effects are introduced. The program's method of handling pre-impact yaw, braking, acceleration and pre-impact steering is outlined.The momentum-based collision model, which relies on restitution rather than vehicle crush or stiffness coefficients, is defined. The program's method for dealing with secondary impacts, inter-vehicle friction, and impulse vectors with a vertical component is explained. The paper concludes with a simple reconstruction which demonstrates the various models and the program's built-in 3D animation capabilities. (A) For the covering abstract of the conference see IRRD 898597.