RESEARCH ON AXIAL HIGH-CYCLE FATIGUE FAILURE OF RUBBER SHOCK ABSORBER

Based on the actual service environment of a rubber shock absorber, the axial loading fixture for the high-cycle fatigue test of the rubber shock absorber is designed. High cycle fatigue tests with a variable frequency, a variable load ratio and a variable fatigue load level of the shock absorber structure are performed by using a high-frequency electromagnetic fatigue testing machine. The difference of micro-morphology for a rubber damping pad before and after the fatigue test is analyzed by three-dimensional tomography equipment. And the fatigue failure criteria of the shock absorbers are determined. Further, the fatigue failure curve and the failure model of a shock absorber are obtained. The analysis results indicate that the current structure of a rubber shock absorber is easy to generate circumferential compression shear cracks, and that the fatigue failure life obtained by asymmetric loading is much longer than that obtained by symmetric loading. Finally, the optimization design is carried out upon the fatigue weak link of the existing shock absorber structure. The fatigue tests indicate that the shock absorbers still have good vibration damping performance after optimization, and that the fatigue failure life of the optimized vibration absorber structure is increased by more than 1000 times.