采用有限元软件MSC.Marc对某抗震用十字形截面的防屈曲支撑内芯进行有限元建模, 求解其焊接后的残余应力, 并对其轴向受力状态进行了分析, 依据求出的结构承载后应力大小及分布情况, 评估焊接残余应力对支撑内芯屈服行为的影响。结果表明: 承载时受焊接残余应力的影响, 内芯局部的应力先达到屈服强度, 此区域(受拉时在右焊缝附近, 受压时在远离焊缝的区域)首先发生屈服, 继续加载后内芯才全部屈服失效; 这使得内芯所承受的轴向拉伸载荷与轴向压缩载荷均小于设计值。

Finite element software MSC.Marc was adopted to establish finite element models for buckling restrained brace inner core with cross shaped section. The residual stress after welding was obtained, and its axial stress was analyzed in detail. Based on the intensity and distribution of the stress in the inner core at load, the influence of the welding residual stress on the inner core yield behavior was evaluated. The results show that yielding occurs first in local area near the welding line at tensile load and away from the welding line at comprssive load, in which the stress reaches yield strength due to the presence of welding residual stress. As the load increases, the inner core achieved total yield failure. So the axial tensile load and axial compressive load on the inner core are less than the designed values.