可更换钢连梁抗震性能试验研究

通过拟静力试验，研究由跨中部消能梁段和两端非消能梁段组成的可更换钢连梁的抗震性能和震后可更换能力。试验共包括4个连梁试件，采用4种不同的消能梁段与非消能梁段连接方式，分别为端板-抗剪键连接、拼接板连接、腹板-螺栓连接、腹板-结构胶连接。试验结果表明：采用端板-抗剪键连接时，连梁的塑性变形和损伤集中在消能梁段，连梁的极限塑性转角可达0.06 rad，具有稳定的滞回耗能能力；采用拼接板连接或腹板-螺栓连接时，消能梁段剪切屈服，连接处摩擦型高强螺栓有不同程度的滑移，连梁的极限塑性转角也可达0.06 rad；采用腹板-结构胶连接时，连接处结构胶开裂导致连梁脆性破坏。在连梁转角为0.02 rad加载后对消能梁段进行更换，采用端板-抗剪键连接的试件更换时间最短，而腹板-螺栓连接的试件能在更大的残余转角时更换。此外，消能梁段在较大塑性剪切变形时伴有轴向变形，导致连梁试件承受较大轴力，连梁的轴力影响需要进一步研究。

Experimental study on seismic behavior of replaceable steel coupling beams

A series of quasi-static tests were conducted to examine the seismic behavior and replaceability of the replaceable steel coupling beam which consists of a central ‘fuse’ shear link, connecting to steel beam segments at its two ends. A total of four specimens were designed and tested, where various types of link-to-beam connections were adopted, including the end plate-shear key connection, splice plate connection, bolted web connection and adhesive web connection. The specimen with the end plate-shear key connection had the inelastic deformation and damage concentrated in the ‘fuse’ shear link. This coupling beam specimen showed very stable hysteresis behavior, with an inelastic rotation capacity of 0.06 rad. For the specimens that adopted the splice plate connection and bolted web connection, the ‘fuse’ link yielded in shear, and slippage of high-strength bolts was observed at the connections. The inelastic rotation capacity of those specimens also reached 0.06 rad. The specimen that adopted the adhesive web connection showed brittle failure, caused by fracture of adhesive. On-site replacement of shear links was demonstrated after the coupling beam specimens experienced 0.02 rad rotation. The end plate-shear key connection was replaced within the shortest time, while the bolted web connection was able to accommodate the largest residual deformation. In addition, large axial forces were observed in the steel coupling beams during the tests, because the shear links developed axial deformation as they underwent large inelastic shear deformation. There is a need to further study the effect of the axial forces of the steel coupling beams.