Feasibility of Auto‐Regressive Simulation Model for Fatigue Studies

Abstract

Experimental results from 20 welded specimens are presented to establish the validity of an auto‐regressive simulation technique for fatigue studies. The key parameter in simulating time histories with the auto‐regressive model is the correlation coefficient of the subsequent extrema of the loading process, which seems to be a useful measure in determining the fatigue damage. The auto‐regressive model can be used to simulate loadings that have unimodal (both rectangular and smooth) power spectral densities. Fatigue estimates with narrowband and somewhat broadband normal and nearly normal loadings are performed. Experimental results indicate that the time histories simulated using the auto‐regressive model produce the same fatigue damage as those simulated by the commonly used Gaussian simulation technique. Fatigue‐life predictions by the commonly used analytical techniques, however, substantially overestimate the experimental results.