Design optimisation of linear structures subjected to dynamic random loads with respect to fatigue life

This work concerns the optimisation of linear two-dimensional planar metallic structures subjected to stationary Gaussian random loads. A strategy intended to improve the design of this category of structures is proposed according to the multiaxial high-cycle fatigue, by varying the thicknesses of the zones where the structure is assumed to be divided. To achieve this goal, a computationally efficient framework for the determination of the fatigue life is firstly proposed. It is based on a frequency formulation of the Sines’ fatigue criterion, adapted according to Pitoiset and Preumont works [1]. Two examples are presented to demonstrate the ability of the methodology to provide better structural topologies.

► This work assesses high-cycle multiaxial fatigue reliability of structures.
► Structures are subjected to vibrations and random loads having non-zero mean.
► It proposes a strategy to produce an optimise design, keeping the weight unchanged.
► It presents examples demonstrating the feasibility of the proposed strategy.