钢框架梁柱节点焊缝损伤性能研究Ⅱ：理论分析和有限元模拟

采用断裂力学理论，依据9个钢框架全焊接梁柱节点局部试件的单向拉伸试验结果，对节点试件的焊缝损伤进行了理论分析和有限元模拟。理论计算表明，简化计算式能够简洁地反映节点开裂情况，但对约束条件、裂纹尺寸的简化会影响计算精度。有限元分析结果表明，焊接孔附近的应力集中和热影响区材料的退化导致节点焊缝断裂易发生在梁腹板焊缝位置和梁翼缘焊缝热影响区，两处开裂概率接近，与试验结果吻合；试件开裂位置由初始缺陷的尺寸、位置和材料断裂韧性共同决定；弹塑性有限元分析能够较准确分析试件开裂位置和启裂荷载，精度较高，为研究梁柱节点焊缝损伤性能提供了一种损伤判断方法和准则。

Study on damage behavior of weld of beam-to-column connection in steel frame Ⅱ:theoretical analysis and finite element simulation

In this paper,the weld damage was studied by theoretical calculation and finite element analysis,which were based on tests of 9 welded beam-to-column connections subjected to monotonic loads.The theoretical calculation reveals that the crack can be simulated by the simplified formula from elastic fracture mechanics.The constraint and the crack length affect the calculation accuracy.The finite element analyses results indicate that,stress concentration around the access hole and material deterioration result in the weld and the HAZ zone cracking,which agrees with the experimental results.Initial defect,location and material toughness affect the crack location.The crack locations and loads can be calculated accurately by elasto-plastic finite element method,which provides a damage behavior analysis method for welded beam-to-column connections.