Analysis of a front sub-frame fatigue strength based on Miner theory

摘要

In this paper, the 3-D model of front sub-frame of a car is established by using software CATIA. And further according to the finite element elementary theory, by using the software Hypermesh and the software MSC Patran, the finite element model of the sub-frame is established, and then the finite element stress analysis is carried on by using the MSC Nastran software. Based on the results of stress analysis, the fatigue life of the front sub-frame is calculated by using the software MSC Fatigue, and the distribution of fatigue life and the value life of dangerous point for the front sub-frame are got, which are compared with the failure of the relative ratio in the fatigue bench testing. A combined method is found based on fatigue bench test and simulation, and this will provide basis for the optimal design of front sub-frame.