Topology optimization of structures subject to random excitations with fatigue life constraints

Abstract

In this paper a topology optimization strategy for randomly excited linear elastic structures with fatigue life constraints is presented. In random vibration it is often convenient to describe the excitation and response in term of function in the frequency domain. The random vibration theory was developed to deal with random excitations and is based on the assumption of excitations fully described by their second order statistical properties: their mean value, their autocorrelation function and also their power spectral density function (PSD). In the light of this, specific frequency formulations [1] of commonly used damage criteria are chosen as fatigue life assessment techniques in the optimization procedure. These frequency formulations are well suited to random vibration problems and give a fast and accurate estimation of the structural fatigue life from the response PSD (stress PSD).