Dynamic Crack Growth Analysis of Aluminum Thin Plates Using Analytical and Finite Element Analysis


In this work, the stresses and dynamic crack growth were studied and analyzed in thin flat plate with a surface crack at the center, subjected to cycling low velocity impact loading for two types of aluminum plates (2024, 6061). Analyticalsolution using classical plate theory by using Levy solution employed to determine stresses induced in plate due to the impact load. The impact load applied at the center of surface plate, was calculated by Hertzian contact law. Stresses with respect to time at the crack tip and the velocity of crack growth were calculated through elastic plastic fracture mechanics equations.The size of plastic zone around the crack tip which caused by impact loadingwas found by Dugdal’s model theory.Numerical analysis using program (ANSYS11-APDL) based on finite element method used to analysis the stresses with respect to time at crack tip and then find the velocity of the crack growth under cycling impact loading.The results show that the stresses increase withincreasing in the crack length (i.e:160Mpa at 7mm and 175Mpa at 10mm for Al-6061 also 140Mpa at 7mm and 165Mpa at 10mm for Al-2024).. It was found that the cumulative number of cycles leads to increase in the stress values with increasing in crack growthvelocity.