RESEARCH ON THE THERMAL FATIGUE BEHAVIORS OF THE COMPOSITES MATERIAL SiCp/A356 USED ON THE HIGH-SPEED TRAIN

Thermal fatigue tests are carried out to the notch specimens made of particle-reinforced composites entitled SiCp/A356 between 20℃ and 300℃. The test results show that the thermal fatigue crack initiation lives of different specimens are relative to the notch radius and specimen thickness. The thermal elastic-plastic finite element method is used to simulate the stress and strain response at the notch root of the thermal fatigue test specimen, and thus the formation mechanism of residual stress is revealed. Then according to the thermal fatigue crack initiation life tests and finite element simulation of the stress-strain, the thermal fatigue strain life curves of SiCp/A356 material are given considering the residual stress. This can give the basis for the thermal fatigue property study of the particle reinforced composite SiCp/A356 used in high-speed train brake disc.