A non-linear energy model of fatigue damage accumulation and its verification for Al-2024 aluminum alloy

A method of fatigue damage accumulation based upon application of energy parameters of the fatigue process is proposed in the paper. Using this model is simple, it has no parameter to be determined, it requires only the knowledge of the curve W–N (W: strain energy density N: number of cycles at failure) determined from the experimental Wöhler curve. A computing Matlab-based algorithm of the fatigue life prediction methodology was developed. The proposed damage indicator is connected cycle by cycle to the Wöhler curve. Cycles were counted with the rain-flow algorithm, and damage was accumulated with this model and with the Palmgren–Miner rule. An experimental verification shows a satisfactory agreement between the fatigue life calculation results by the proposed model and test results. Estimated and experimental lives are found to exhibit good agreement. ► A non-linear energy-based damage model for the fatigue life assessment has been proposed. ► Model proposed is connected cycle by cycle to the Wohler curve. ► Model predictions are in very good agreement with the experimental data.