Uncertainty-Based Analysis of Random Load Signal and Fatigue Life for Mechanical Structures

Abstract

In the course of driving, due to the influence of environment, signal acquisition device and the degree of unevenness of road surface, the collected signals fluctuate within certain error range and have randomness. To predict the fatigue life of mechanical structures more accurately, the processing method of random load signals for uncertainty is proposed. The collected load signals are converted into interval load signals by Bootstrap error circle method, and based on the generalized Pareto distribution, the peak-over-threshold extrapolation is performed on the interval load signals. Based on the mixed probability distribution model, the one-dimensional and two-dimensional interval load spectrum for shock absorber cylinder are established by analyzing the characteristics of load signals. In addition, based on the uncertain signal problems, the interval life spectrum and interval damage spectrum of one-dimensional and two-dimensional are constructed by the interval algorithm. This paper lays a foundation for load signals processing and fatigue life prediction of parts.