A model and optimization method used for vehicles velocity calculation of non-central crash accident

In order to satisfy request for an effective method to analyze complex accidents, the studies of car-car accidents characterized by non-central collision have been underway by our group. Here a converse analysis model is put forward. Vehicle collisions are classified into central collisions and non-central collisions. Non-central collisions are further classified as non-central point collision and non-central surface collision. After introduction of assuming and vehicle velocities calculation of simple central collision, a serial of resolving steps begins from an impact surface defining. Then the three coordinate systems used for describing collision are set up with vehicles impact part position for non-central collision. In the impact surface coordinate system momentum equations can be founded according accident mechanics. For non-central point collision, it needs introduce spring resume coefficient and tangent friction coefficient of the impact point. By transforming in coordinate systems matrix equation in world coordinate system are founded. For non-central surface collision, firstly assumed an impact point and normal composition point, then added normal impact moment around impact point into matrix equation, at last taken distance between impact point and normal composition point as parameter. Taking angle between original vehicles direction and calculated direction as object, used parsing or program method to optimize the results. Our actual cases studies indicate that the model is validated and is becoming to local conditions.