焊接接头中的裂端应力三轴性

采用弹塑性有限元方法研究了平面应变条件下裂位于焊缝中心不同强度匹配和裂纹深度焊接接头的裂端应力三轴性。结果发现，与均匀材料相比，同等载荷水平下，高匹配接头裂端应力三轴性降低，低匹配接头裂端应力三轴性升高；随裂纹变浅，应力三轴性降低，强度匹配的影响也更为显著。从焊缝和母材塑性变形与应变硬化交互作用方面进行了解释。

Crack tip stress triaxiality in welded joints

The investigation of the crack tip stress triaxiality of welded joint containing a central crack in the weld metal whose yield strength and crack depth may be varied using an elasto plastic finite element methodunder plain strain, and reveal that the stress triaxiality ahead of crack tip tends to increase for under matched weld and decrease for over matched weld using the even matching case as a references and as the crack length reduced for a given specimen width, the stress triaxiality decrease accordingly and the effect of strength mis matching becomes more obvious, and these can be explained in terms of plastic deformation and strain hardening interaction between weld metal and base material.