Fatigue Life Analysis and Experimental Study of a Broadband Non‐Stationary Stochastic Process With Mean Stress

ABSTRACT This paper presents the fatigue life analysis and experimental study on a broadband non‐stationary stochastic process with mean stress. An experimental platform capable of simultaneously applying random vibration loads with mean stress and periodic loads to specimens is first constructed, thereby inducing non‐stationarity in the vibration response. Vibration fatigue tests on edge‐notched 6063‐T6 aluminum alloy specimens verify the influence of both the mean value and non‐stationarity of the stochastic process on vibration fatigue life. A novel model is subsequently developed for predicting the fatigue life under broadband non‐stationary stochastic processes with mean stress. This model quantitatively accounts for the effects of mean stress, as well as the amplitude and frequency of periodic loads, on vibration fatigue life. The results of the vibration fatigue tests indicate that the proposed model provides accurate fatigue life of the broadband non‐stationary stochastic processes with mean stress in the frequency domain.