The Research of Numerical Simulation with Variable COD for Aluminum Alloy

Materials of aluminum alloy, a kind of lightweight material, were employed widely in the field of engineering. For the research of friction stir weld's joints of aluminum alloy under different welding parameters, It is found that the value of critical crack opening displacement (|CODcritc|) is constant when stable crack growth and hereby tried to suggest that the |CODcritc| as a fracture parameter to establish one fracture criterion in order to optimize the welding parameters. But the |CODcritc| is variable on the initial stage of unstable crack growth, if the constant on the stable stage was introduced in the simulation to analyze the whole course of the crack development, the results of the simulation would be not accuracy enough. Therefore, the other criterion, the introduction of the function curve of |CODcritc|, was proposed and could solve the related problems very well. Using the software of Franc2D/L to build the Arcan model of Aluminum Alloy 2524-T351 (short in AA2524), compare the results of simulation to the experiment and also compare the results from two criterions.