2003 Volume 21 Issue 3 Pages 419-424
The purpose of this study is to investigate whether experimental results of static fracture strength of lap joint made by laser welding can be predicted by numerical analysis or not. First, numerical analytical method was devised for estimating the experimental result of the relationship between load and displacement of shear test. Next, experimental result of static fracture strength was predicted by using the concept of critical equivalent plastic strain, that the lap joint is fractured when maximum equivalent plastic strain reaches a critical value. The static fracture strength of lap joint was predicted by the concept of critical plastic strain when fracture occurs in the base metal. However, when lap joint was broken by shear fracture in the joint part, shear strength of lap joint could not be predicted by the concept. The shear strength of lap joint could be predicted from the shear strength of weld metal.