FE Modelling and Experimental Evaluation for the Surface Integrity of Thin-Walled Aluminum Alloy

The present study discusses the effect of installation torque on the surface and subsurface deformations for thin-walled 7075 aluminum alloy adapters used in Aerospace applications. An FE model was constructed to predict the effect of torque-induced stresses on thin-walled geometry validated with experimentation. A detailed surface analysis was performed on 7075 aluminum to check superficial discontinuities, residual stresses, and grain deformations. The localized strain hardening resulting from increased dislocation density and its effect on surface microhardness was further studied using SEM (Scanning Electron Microscope). The predicted surface level plastic strain of .25%, on the castle nut adapter, was further validated with grain deformations measured using optical and scanning electron microscopy.