Abstract: As a typical kind of traffic accident, vehicle-pedestrian collision contains vehicle, pedestrian and ground which is a multi-body system and involves lots of variables, making it rather difficult to build the reconstruction model. Among all the input variables, pedestrian-ground friction coefficient is one of the most important ones and has a decisive effect on the final computation result. Friction coefficient is usually considered as constant value in traditional traffic accident reconstruction which is far from the real physical case and thus engender fairly great error in computation. The nonlinear relationship of contact friction between pedestrian and ground is investigated based on the simplified physicalmodelof fiber-rough road surface contact. Method of construction the function about friction coefficient and normal force in car-pedestrian collision traffic accident is also proposed and a real case is employed to verify the validity of the above method. The analysis indicates that model constructed by the above method can greatly reduce the deviation between simulation and real case, which may provide more convincing technical basis for the traffic accident identification. The idea of applying the principle of contact friction mechanics to the traffic accident reconstruction also gives some reference for further exploration.

Key words: car-pedestrian traffic accident, friction, nonlinear, numerical simulation