Study on the machining distortion of aluminum alloy parts induced by forging residual stresses

A weak-rigid monolithic component is subjected to significant distortion after the removal of material. This condition is principally due to flexibility of the part and the release of initial residual stresses resulting from fabrication. This article reports a systematic study on the measurement of initial residual stresses and the distortion of a windshield frame part induced by material removal from the forged blanks of aluminum alloy 7085-T7452. A layer-removal method was employed to measure the stress profiles of the blank. The stresses after analytical correction were found to be closer to actual condition. The effect of material removal on distortion from stressed blank was investigated using the finite element analysis software ANSYS. The simulated results indicate that after the proportion of removed material exceeds 60%, part distortion becomes stable. The comparisons of the simulation with experimental data suggest sufficient agreement with conclusion that the use of finite element analysis proves to be an attractive and reliable method for predicting stress-induced distortion.