Analysis Of Fatigue Characteristics Of Car Subframe Structure

The strength of chassis structure is one of the important factors related to vehicle safety. As for the general structure damage under poor conditions, the personal safety and property losses are generally smaller because the speed is always low. The cumulative fatigue damage of the mechanical structure occurs under various working conditions. Once the accumulated fatigue damage reaches a critical value, damage occurred. It can cause irreparable damage if fatigue failure occurs when the vehicle traveling at high speed.In this paper, taking a front suspension subframe which is from a business as an example. The analysis of simulation is according to the static strength of structure in poor conditions and Fatigue strength in test field conditions, provides a reliable and effective reference to the structural design work. First of all, the front suspension and full vehicle rigid flexible coupling dynamics model was built by a multi body system dynamics software ADAMS/CAR. The sub frame and stabilizing bar using a variety of schemes to construct model, and compared with the prototype K&C test data to verify the correctness of the dynamics model. Then using finite element static balance algorithm and the modal superposition method to simulate the poor static conditions and compared two results to verify the correctness of the application of modal superposition method in this paper in the dynamics model. At last, using the simulation of vehicle dynamics model in the rough cement pavement under virtual test field to extraction of modal superposition time history as the factor load spectrum. The subframe fatigue strength for this study was calculated and analyzed, provides reference for structure design of side frame.