Reliability based design optimization for multiaxial fatigue damage analysis using Matsubaraˆas criterion developed in the frequency domain of structures under random vibrations

This study aims to an optimal design of a structure subject to random
vibrations, considering fatigue damage, that guarantees a required reliability level
under uncertainties parameters. In practical applications, structures are exposed
to multiaxial random loading. While numerous fatigue life prediction criteria
have been developed primarily in the time domain, frequency domain methods are
preferred for reducing computational calculating time in fatigue damage analysis.
In this study, we present a numerical strategy that leads to determine the multiaxial
fatigue damage of structure under random vibrations using Matsubaraˆas criterion
developed in the frequency domain. To ensure the proper functioning of a
component, it is important to consider uncertainties from the design stage.
This work presents a methodology to find the best adjustment between cost and
safety. Accordingly, several methods are developed, such as the Hybrid Method
(HM) and the Robust Hybrid Method (RHM) to attain this purpose. Here,
we present an extension of these approaches in case of structures under random
vibrations. The obtained results showed the effectiveness and efficiency of the RHM
for treating the RBDO problem of structures subject to random vibrations with
fatigue damage constraint. The different RBDO methods are treated by interfacing
between MATLAB and Ansys as finite elements software.