软夹硬力学不均匀焊接接头疲劳裂纹闭合行为的实验研究

Experimental Research on Behavior of CrackClosure in Heterogeneous Welded Joints

力学性能不均匀是焊接接头的三大特征之一，本文采用柔度法研究了不同硬夹层宽度的软夹硬力学不均匀焊接接头疲劳裂纹的闭合行为。研究结果表明，裂纹尖端附近软区的局部屈服在疲劳载荷卸载过程中促使裂纹闭合。随着硬夹层宽度的减小，这一影响越来越明显。

Mechanical heterogeneity is a basic characteristic of welded Joints. In this paper, welded joint wassimplified by a rnodel SHS (hard layer between soft material with a crack parallel to interface in thesandwiched layer), and behavior of fatigue crack closure of this model being studied. It was foundthat, local yielding in soft zone adjacent to crack tip promotes crack closure during fatigue unloading.The narrower the hard layer,the significant the effect.