Effect of edge distance ratio on residual stresses induced by cold expansion and fatigue life of TC4 plates

A finite element model is used to analyze the residual stress distribution around a cold expanded hole in a TC4 plate with various values of the edge distance ratio. The fatigue life of cold expanded hole is predicted using two models based on the critical plane approaches: SWT model and WB model. The predicted values are also compared with experimental results. The results show that the WB model achieves a better accuracy for cold expanded holes. When the edge distance ratio decreases, the residual tangential compressive stress and fatigue life of a cold expanded holes decrease.