Optimization design and fatigue life analysis of damping conical rubber spring for rail vehicle

Abstract

The fatigue life prediction model for rubber materials is built by using the equivalent tearing energy method. The finite element model of a damping conical rubber spring for rail vehicles is established by using ABAQUS software. The finite element numerical simulation results show that the stiffness coefficient, and fatigue life as well, does not satisfy the structural design requirements. The influence of geometric parameters of the conical rubber spring on its fatigue life is analyzed by using the orthogonal numerical test method. The results show that the thickness and length of the first rubber layer significantly affect the fatigue life of the structure, and the thickness of the fourth rubber layer has the least effect. Taking the minimum strain as an optimization objective and the geometric parameters determined by the orthogonal numerical tests as the design variables, the second-order response surface model is established, and the Multi-Island Genetic Algorithm is used to carry out the single objective multi-factor optimization design for the rubber spring under the condition of stiffness constraint. The results show that the stiffness coefficient of the optimized structure is 0.630kN/mm, which falls within the range of the design stiffness coefficient, and the fatigue life is 4.963 million cycles, while the design fatigue life is 3.500 million cycles, so the fatigue life and stiffness all reaches the design requirement. The test verification indicates that the calculated fatigue life is well fit with the test one, and the simulated fatigue failure position is consistent with the test.