Abstract: A vehicle-track system dynamic model, including multipoint contact wheelset vibration equations, is built to carry out curve negotiation verification of a new calculation and decision method for wheel-rail multipoint contact¬─trace line extremum method. The position of curve negotiation contact points on the wheel tread, the number of wheel-rail contact points and the wheel-rail normal force are presented. The result shows that the trace line extremum method can solve the wheel-rail multipoint contact problem and obtain the accurate geometric parameters of wheel-rail multipoint contacts and the system vibration characteristics. When two-point contact of wheel flank root and wheel flank occurs, the result obtained by using multipoint contact method is more reasonable and reliable than that by using single-point contact method. If no simultaneous two-point contact of flank root and flank, the results by multipoint contact method and by single-point are almost in full agreement. Compared to the new wheel tread, the worn tread is easy to form two-point contact nearby the depression area of the nominal diameter position of wheel tread. The correctness and effectiveness of the new method are verified.

Key words: Dynamic curve negotiation, Flange root contact, Multi-point contact, Tread wear