A nonlinear damage accumulation model for shakedown failure

This paper presents a nonlinear damage accumulation (NLDA) model for shakedown failure of materials and structures subjected to high amplitude, low cycle load history capable of producing substantial plastic strain. This NLDA model is formulated based on energy principles coupled with a cumulative damage parameter that accounts for the progressive damage accumulation dictated by the path of the load history without any requirement for counting of cycles as have been done in current practice. The shakedown failure of metals subjected to constant, high amplitude, strain controlled loading cycles predicted by the NLDA model agrees well with the experimental data reported in the literature. Effect of sequence of load history to damage accumulation is demonstrated through numerical examples.