Experimental Investigation of High-cycle Fatigue Behavior for Automobile Structural Steel Based on Stress-Number-of-cycles Curves

摘要

An experimental sensing system and performance analysis of the measurement of the high-cycle fatigue properties of automobile structural steel are presented. Firstly, the yield strength and tensile strength of the automobile body stamping steel plate are determined through a static uniaxial tensile test. In accordance with the stress ratio R = 0.1, the stress at all levels is determined, and the tensile strength test based on stress is carried out. Secondly, the fatigue data obtained using Goodman's and Gerber's empirical formulas are modified to eliminate the effect of average stress. The fatigue analysis software program LabMOTION is used to acquire the stress-number-of-cycles (S-N) curves of the material under different failure probabilities, and the fatigue limit of the material is obtained as well. The experimental results indicate that this method can be used to obtain the real fatigue characteristics of materials and that the fatigue limit obtained through Gerber's empirical formula and the slope of the S-N curve of a finite-life region is more accurate. In this study, we provide a reference for future automobile body fatigue simulation analysis, parts design, and general product quality.