平齐端板连接偏心支撑钢框架抗震试验研究

Experimental study on seismic behavior of eccentrically braced steel frame with flush end plate connection

为研究耗能梁段长度和柱轴压对平齐端板连接偏心支撑钢框架抗震性能的影响,进行4个偏心支撑半刚接钢框架的低周反复荷载试验,并从滞回曲线、承载力、延性、耗能及螺栓应变等方面分析了试件的抗震性能.试验结果表明:平齐端板连接偏心支撑钢框架破坏模式为耗能梁段端板焊缝或腹板断裂,其余构件均未出现明显屈曲变形和裂纹,易于震后修复和更换耗能梁段.耗能梁段长度是偏心支撑半刚接钢框架抗震性能的重要影响因素之一,随耗能梁段长度比的增大,极限承载力及累计耗能均呈下降趋势,短耗能梁段试件的承载力高于长耗能梁段试件的,由于构件之间的滑移,平齐端板连接偏心支撑钢框架结构滞回曲线呈现不同程度的捏缩现象,且随着耗能梁段长度增加,捏缩现象愈加明显.

In order to study the influence of link length and axial force on the column on seismic behavior of prefabricated eccentrically braced steel frame,the pseudo-static test of four eccentrically braced steel frame with semi-rigid joints were carried out.The hysteretic curves,loading-carrying capacity,ductility,energy dissipation and strain of bolts in specimens were investigated to evaluate the seismic performance.The test results show that the failure mode of the eccentrically braced steel frame with flush end plate and bolt connection is the end plate weld or web fracture of the energy-dissipating beam segment,and there is no obvious buckling deformation or cracks appear in the rest of the link,which is easy to repair and replace the link after the earthquake.The length of the link is one of the important factors affecting the seismic behavior of eccentrically braced frame with semi-rigid joints.The bearing capacity of the specimens with short link is higher than that of specimens with long link.Due to the slippage between members,the hysteresis curve of specimens of flush end plate connection presents different degrees of pinching,and pinching becomes more obvious as the length of energy-dissipating beam segment increases.