焊接接头非均匀力学性能对J积分和失效评定曲线的影响

由于焊缝填充金属的不同和焊接热循环的作用，焊接接头不同区域有着不同的力学性能。本文将焊接接头模化为由两种材料组成，即母材金属和焊缝金属，用弹塑性有限元分析法计算了焊接接头强度组配对Ｊ积分和失效评定曲线的影响。结果表明，焊接接头不均匀强度组配对裂纹驱动力－Ｊ积分和失效评定曲线的形状与位置有很大影响。对于一个特定的焊接接头，如果接头为低组配或等组配，则以母材金属的极限载荷作为无因次载荷而建立的安全评定

Effect of Heterogeneous Mechanical Properties in Welding Joint on J Integral and Failure Assessment Curves

Due to the choice of the weld metal and the local thermal cycle,the weld joint because heterogeneous in mechanical properties for different region.In this paper,the weld joint is modeled to consist of two materials,namely the base metal and weld metal.The influence of strength mismatching factor,ratio of yield strength of weld metal to that of base metal,on the J integral and failure assessment curves was studied by using elastic plastic finite element method for Center cracked panel(CCP) specimens.The results indicated that the strength mismatching of weld joint has a great effect on the value of J integral and the shape of failure assessment curves.For a given weld joint specimen,the shape and position of failure assessment curves are different for the applied load normalized respectively by the base metal limit load and weld metal limit load.In practice,It is more safety to establish the failure assessment diagram using the limited load,which has a higher strength for base metal and weld metal,as the normalized load