Strain Behavior at Crack Tip in Thin Plate Using Numerical and Experimental Work

Abstract

In this work, strains were studied and analyzed in a thin flat plate with a surface crack at the center, subjected to cycling of low velocity impact loading for two types of aluminum plates (2024, 6061). Experimental and numerical methods were implemented to achieve this research. Two cases of boundary conditions were used in this study; clamped-clamped with simply supported at the other edges, and clamped-clamped with free at the other edges. Numerical analysis using program (ANSYS11-APDL) based on finite element method used to analyze the strains with respect to time at crack tip. In the experimental work, a rig was designed and manufactured for cyclic impact loading on the cracked specimens. The grid points was screened in front of the crack tip to measure the elastic-plastic displacements in the x and y directions by grid method, from which the strains are calculated. The results show that the strains increase with increasing the crack length. It was found that the cumulative number of cycles leads to increase in the strain values.