Fatigue behavior of interference fitted Al-alloy 7075-T651 specimens subjected to bolt tightening

Abstract

Interference fit process is extensively used in bolted and pined joints having different fatigue behavior compared to plain hole specimens. In the present research, fatigue behavior of interference fitted specimens subjected to bolt clamping force has been investigated. The objective of the present study is to extend the present knowledge about the fatigue behavior of interference fitted holes by investigating the subsequent bolt clamping force effect based on the experimental and numerical results in Al-alloy 7075-T651 plates. To investigate the effect of bolt tightening on the fatigue life of interference fitted specimens two tightening torque levels were employed. Fatigue tests were performed to obtain S–N curves and failure modes of interference fitted bolt clamped specimens. Circumferential pre-stress distribution created by interference fit and bolt clamping has been analyzed by finite element method. The finite element analyses justify the experimentally observed fatigue test behavior. The fatigue test results demonstrate that bolt clamping force applied on interference fit plays a positive effect on fatigue behavior and prolongs the fatigue life.