The effect of elevated temperature on LCF damage growth in 2024AA – Experiment and modeling

Abstract

This paper presents the results of experimental low-cycle fatigue (LCF) tests conducted on EN-AW 2024 alloy in T3511 temper at 100 °C, 200 °C and 300 °C. The material's basic fatigue characteristics were determined, such as fatigue life curve and cyclic strain curve. Both the hysteresis loop and nature of fracture surfaces obtained in macro- and microscopic observations (scanning electron microscope, SEM) were accounted for. The results of tests at elevated temperature were compared with results obtained at room temperature in the authors’ previous papers. Based on the results of experimental tests, an analytical model of fatigue damage growth was proposed. In this model, it was assumed that damage accumulation mainly depends on the current normal stress and increment of plastic strain. Dependencies of the model's parameters with respect to temperature were determined, and the model was validated experimentally. Good concurrency of the numerical simulations with the experimental results was obtained.