The effect of Installation Sequence and Distance between Pins on Distribution of Residual stress and Edge Crack Growth in Single Hole Specimens

The effect of installation sequence and center-to-center distance between pins on distribution of residual stresses and edge crack growth of single hole specimens under the fatigue loading are investigated. Hole edge cracks are observed in some industrial components similar to gas turbine casing. Residual stresses distribution induced in three-dimensional holes analyzed and redistribution of residual stress in adjacent holes are investigated. Finite element (FE) analysis on specimens similar to gas turbine casing of ductile cast iron were conducted and the behavior of material was assumed elastic– perfectly plastic. Mechanical fatigue crack growth is predicted by using Abaqus software and Zencrack fracture mechanics code. The results show that the mechanical fatigue life affected by variations in the installation sequence and distance between pins. When the second pin is installed, a residual stress relaxation process occurs near the first hole due to the secondary yielding produced by the expansion of the second hole, this redistribution of residual stress caused a decrease of fatigue life near first hole. Consecutively, the results from the numerical predictions were compared with the experimental data.