外伸端板SMA螺栓连接自复位钢框架去柱抗倒塌性能分析

Collapse resistance of the self-centering steel frame by extended end-plate connections equipped with shape memory alloy bolts under a column removal scenario

为明晰外伸端板形状记忆金属(Shape memory alloy,简称SMA)螺栓梁柱连接自复位钢框架去柱后结构的抗倒塌性能,采用ANSYS软件建立了梁、实体混合单元模型。在验证有限元模型合理的基础上,进行外伸端板SMA螺栓、高强度螺栓柱连接去柱子结构竖向加载分析,并对比两类试件的受力性能及复位效果。研究表明:两类试件应力(应变)分布相似,且应力集中在外伸端板上侧及梁翼缘与端板连接处;中柱竖向力-位移曲线呈三段式分布,SMA螺栓连接试件加载后期悬链作用显著,且竖向承载力高于高强度螺栓连接试件;SMA螺栓连接可有效减小结构残余变形,降低结构的修复难度,提高修复的经济性。

To investigate the collapse resistance of the self-centering steel frame by extended end-plate connections equipped with shape memory alloy bolts subjected to sudden column removal scenario,finite element model with beam and solid mixture elements is carried out using ANSYS software. After the rationality of the finite element model is verified,the beam-column connection substructures of steel frame equipped with shape memory alloy bolts and high strength steel bolts are designed,and analyzed under a column removal scenario by nonlinear static analysis. Then the mechanical performances and self-centering effect of the two specimens are compared. The results indicate that the stress( strain) distribution of both specimens is similar,and the stress is concentrated on the top side of the extended end plate and connection between beam flange and end plate. The vertical forcedisplacement curve of the middle column shows a three-segment distribution,the catenary effect of the SMA bolt connection specimens is significant at the last loading stage,and the vertical bearing capacity is higher than the high strength bolted connection specimen. Connection with shape memory alloy bolts can effectively eliminate the residual deformation,reduce the difficulty of repairing,and improve the economy of repairing.