钢框架结构阻尼支座楼梯抗震性能研究

为研究钢框架结构阻尼支座楼梯的抗震性能，设计并制作缩尺比例为1∶2的阻尼支座楼梯和固定支座楼梯试验模型，在恒定轴力作用下对其分别进行拟静力试验。试验中研究了不同楼梯的破坏形态、滞回性能、耗能性能、变形能力等，分析了不同楼梯的工作机理。试验结果表明：阻尼支座楼梯通过阻尼支座耗能，改变了楼梯的传力途径和内力分布，而固定支座楼梯通过构件自身损伤耗能，破坏阶段固定支座楼梯的平台板、斜梯梁节点和梯梁等变形较大，框架梁屈曲严重导致不能继续加载；两种楼梯的滞回曲线都较为饱满，阻尼支座楼梯加载初期刚度较小，后期其刚度达到甚至超过固定支座楼梯，有较好的承载能力；阻尼支座水平方向滑动位移较大，有利于阻尼器发挥作用，其竖向位移基本可以忽略不计，阻尼支座竖向刚度有效控制了踏步板的翘起。

Seismic behavior of damping bearing stairs in steel frame structures

In order to study the seismic performance of stairs in steel frame structures,two 1∶ 2 scaled test models of stairs with damped supports and fixed supports were designed and manufactured,and the quasi-static tests were carried out under constant axial force. The failure modes,hysteresis performance,energy dissipation performance and deformation capacity of different stairs were investigated,and the working mechanism of different stairs was analyzed.The test results show that the energy dissipation of the staircase with damped supports is through damping effect,which changes the way of force transmission and internal force distribution of the staircase. The energy dissipation of the staircase with fixed supports is through the damage of the component itself. In the stage of failure,the deformation of the platform plate,the joint of the inclined beam and the staircase beam of the staircase with fixed supports is large,and the severe buckling of the frame beam causes the failure of bearing capacity. The hysteretic loops of the two stairs are full and plump. The stiffness of the stairs with damped supports is smaller in the initial stage of loading,but later reaches or even exceeds that of the stairs with fixed supports,indicating better bearing capacity. The horizontal sliding displacement of the damping support is larger,which is beneficial to the damper,and the vertical displacement can be neglected. The vertical stiffness of the damping support effectively controls the warping of the pedal.