Investigation of the fatigue behavior of open cell foams by a micromechanical 3-D model

This work is concerned with an analysis of fatigue damage accumulation and failure of open cell metal foams. For an efficient numerical analysis, a failure event based simulation procedure is proposed, which considers the failure of individual struts as particular discrete failure events governing the degradation of the foam microstructure during cyclic loading. In a simplifying approach the cyclic stress-strain-response between the discrete failure events is assumed to be independent of time. In conjunction with Miner's rule for the description of the fatigue damage accumulation within the individual struts a numerically efficient computational scheme is obtained, requiring the simulation of only a limited number of cycles. The microscopic results are transferred to the macroscopic level by means of a strain energy based homogenization procedure. In a number of parametric studies on the fatigue behavior of Kelvin foams and a comparison with experimental data, the proposed computational scheme proves to be both accurate and numerically efficient