Abstract: A new geometric wheel-rail contact algorithm，the space vector mapping method, is presented to solve the railway vehicle dynamic wheel-rail contact problem. Based on the space vector mapping principle and the basic characteristics of wheel-rail shape, this method regards the wheel-rail contact as space surface contact, chooses the track cross-section as a reference and views the track surface width as the possible maximum contact range of the wheel-rail. Then it adopts certain contact point search and verifying principles so that the dynamic contact point of the wheel in postures of different lateral displacement and yaw angle can be accurately located. With a set of self-composed wheel-rail interaction software TPLWRSim, taking LMA wheel tread as an example, a three-dimensional models of wheel/rail, wheel/roller and wheel/trough type rail are established respectively, which can simulate the wheel-rail contact state under different conditions. Comparing the results with the geometry shape of wheel-rail contact and the geometry contact relationship of worn tread verifies the accuracy and effectiveness of the algorithm. Simulation results show that this algorithm can solve the problem of wheel-rail and wheel-wheel contact and quickly and accurately determine the contact point between the wheel and the track in any postures, and also verify a good adaptability to treads and rail with different shapes.

Key words: contact line method, LMA, space vector mapping method, wheel-rail contact, wheel-roller contact