Elastic-plastic analyses of multiple site damages in aluminum sheets using finite element alternating method

This paper presents elastic-plastic analyses of Multiple Site Damages (MSD) in aluminum sheets, which contain one large crack at the center with several small cracks in front of its tips, subjected to far field tension loads. The analyses is performed based on the T*-integral fracture parameter, using the recently developed elastic-plastic finite element alternating method. A T*-resistance curve is obtained from the numerical simulations of experiments of center-cracked panels containing single cracks, in the generation phase analyses. A number of numerical predictions are made in the application phase, using the T*-resistance curve obtained in the generation phase. The predicted curves of load versus crack-extension are compared with the experimental measurements obtained at National Institute of Standards and Technology (NIST). Good agreements are observed. Through this comparison, the present paper presents, for the first time, a truly validated energy based fracture criterion for the analysis of stable growth and link-up of multiple cracks in an MSD situation.