Study On Accelerated Durability Test Method Of Off-road Vehide Suspension System

Fatigue is the main failure mode of vehicle suspension system and fatigue durability of automobile suspension becomes more important for users and enterprises.Fatigue durability test theory and method of automobile suspension is an important research direction in automobile test field.Vehicle endurance test load spectrum acquisition,accelerated test load spectrum generation and indoor road simulation test method are taking into consideration.Obtaining suspension components load spectrum by virtual iterative technique is explored.The results of fatigue test and road test of off-road vehicle suspension validates the method.The main contents are as follows:①Vehicle response signal acquisition for road simulation test:According to the needs of iterative road spectrum,determine the number and type of signals,build signal acquisition system.The data acquisition was completed in the off-road and intensified road of Dingyuan Automobile Test Field.②Accelerated test load spectrum generation:Spike filter,drift correction and FIR filter are processed by pretreatment technology,and the data normality and data smoothness are tested.Rain flow method and material S-N curve are applied to calculate the frequency distribution and damage distribution of load cycles.The principles of load spectrum editing are put forward.Theoretical accelerated load spectrum generation is accomplished considering damage reservation and PSD.Considering the capability of the test bench,the data can be processed with minimizing distortion of the load spectrum with which the load spectrum of the accelerated test can be generated with high precision.③Virtual iteration to obtain the boundary load spectrum of components:The multi-body dynamics model of the whole vehicle is established in ADAMS/CAR,and the dynamic responses of suspension key parts are obtained by virtual iteration,which are the basis of fatigue life analysis.④Road simulation accelerated endurance test:The identification of FRF of the simulation system is performed with the white noise signals.The iterative process based on the FRF continues until the response errors of acceleration signals at the center of tires converge to an acceptable tolerance level,and the tire excitation signals from the test rig are obtained.200 hours of vehicle road simulation accelerated endurance test result are compared with the actual road test vehicle failure to validate the road simulation accelerated durability test.