Spectral methods for lifetime prediction under wide-band stationary random processes

Abstract

Fatigue damage under wide-band Gaussian random loading is analysed. Numerical simulations on power spectral densities with different shapes are performed in order to establish proper dependence between rainflow cycle counting, linear cumulative fatigue damage and spectral bandwidth parameters. In particular, comparison is made between numerical results and some analytical prediction formulae available for fatigue damage evaluation; amongst all expressions, a new proposed original approach is shown to give sound theoretical framework and improved results. Moreover, a simple application, concerning a discrete parameter model subjected to road irregularity, follows, confirming the validity of the new proposed method.