Evaluation of continuum damage at different temperatures for aluminum-silicon alloy of engine piston within low-cycle fatigue regime

In this article, the isothermal low-cycle fatigue continuum damage in the engine piston aluminum alloy has been evaluated at different temperatures. For this objective, experimental data of low-cycle fatigue tests on standard specimens were used at 280, 350 and 425°C. Based on the continuum damage mechanics method, the fatigue damage was calculated during cyclic loading. Obtained results, including the predicted low-cycle fatigue lifetime of the piston aluminum alloy, indicated that based the maximum value of the relative error and the average error, a proper agreement was achieved, compared to the experimental fatigue lifetime. Applying the continuum damage mechanics approach in each temperature level in a separately condition, reduced significantly the relative error. Then, properties of the engine piston aluminum-silicon alloy based on the continuum damage mechanics model were obtained versus the temperature, under cyclic loadings. Finally, different damage parameter were defined and their results were compared to results of the continuum damage mechanics technique and the superior parameter was defined and selected.