硬夹层中含裂纹的非均质焊接接头的COD研究

本文将焊缝中含有裂纹的高匹配焊接接头或HAZ硬化区中含有裂纹的焊接接头以及过渡层较硬且其中含有裂纹的异种金属焊接接头简化为硬夹层中含有裂纹的非均质中心裂纹板，裂纹平行于硬夹层与软区的分界。用弹塑性有限元方法和云纹实验应运地这种模型的应变场、断裂参量COD等进行了研究。研究结果表明，材料的不均匀性对COD的影响是不可忽略的，特别当名义应力或名义应变较高时更是如此。COD随硬夹层宽度的增加而减小。

A COD ANALYSIS OF HETEROGENEOUS WELDED JOINTS WITH A CRACKED TRANSVERSE SANDWICHED HARD LAYER

In this paper, overmatched welded joints with a crack in a hardened HAZ, and welded joints of dissimilar metals jointed through a harder transition layer with a croak in it are simplified and modeled as heterogeneous plates with a sandwiched hard layer containing a centre crack parallel to the bonds. The strain field and the COD in the heterogeneous centre-cracked plated are studied both numerically by elastoplastle FEM and experimentally by Moiré method. The results obtained show that the effect of the material heterogeneity upon the COD is non-negligible especially in case of the nominal stress or nominal strain being comparatively high. The COD decreases with the increasing sandwiched hard layer width.