Evaluation of bolster spring faults on heavy haul wagon dynamic behaviour

This paper focuses on a deterioration evaluation of bolster spring faults on the dynamic behaviour of a heavy haul wagon. Simulation methods are applied instead of test methods, due to the advantages of zero-dangerousness and easy implementation. Bolster spring fault conditions are discussed in the 2nd section and 20 fault conditions are proposed with two fault levels and four fault locations. A typical 40t axle load heavy haul wagon is focused on and a fully detailed dynamic model of this wagon is developed in the 3rd section considering the nonlinearity of the bolster spring stiffness. The bolster spring performance, carbody responses and wheel-rail dynamic are compared and analysed under the proposed bolster spring fault conditions in the 4th section. Evaluation results show that the bolster spring faults could only affect the spring travel of the “faulty” bolster springs, have the most dramatic influences on the vertical carbody acceleration in the carbody responses and the vertical wheel force in wheel-rail dynamic.