关键词: 三明治板, 激光焊焊接接头, 三向应力度, 等效断裂应变

Abstract:

In order to achieve mechanical property under different stress triaxiality at tensile test from sandwich plane laser-welded joint of hull steel CCS-B, the flat grooved specimens with different radius and sizes were designed to study the effects of the stress triaxiality on the fracture plastic strain. The different stress triaxiality was determined by groove radii and the specimens' size. The results indicate that: whether the specimens are at the state of plane stress or plane strain, the strength of welded joint increases and meanwhile the plastic of weld joint decreases with increasing of initial stress triaxiality. The relationship of the initial stress triaxiality and the equivalent strain to fracture were fitted using an exponential function. The fracture equivalent strain decreases with increasing of stress triaxiality. The fracture surface of specimens are mainly dominated ductile fracture with more dimple.

Key words: sandwich plane, laser-welded joint;stress triaxiality, equivalent fracture strain