采用新型摩擦耗能节点立体停车结构抗震性能分析

Analysis on Seismic Performance of 3D Parking Structure Using New Energy Dissipation joint

针对钢结构梁柱节点在地震中经常发生脆性破坏的问题,在采用角钢连接的钢结构梁柱节点(以下简称角钢节点)基础上,在梁腹板处添加槽钢,将圆形螺栓孔改为长圆孔,提出一种主要利用摩擦来耗能的新型钢框架梁柱耗能节点(以下简称耗能节点)。首先,采用有限元软件ANSYS建立了耗能节点和角钢节点的精细化有限元模型,对两种节点的精细化有限元模型施加了单调静力荷载,对比分析了两种节点的受力机理、弯矩-转角特性、力学性能。其次,对两种节点的精细化有限元模型施加了低周反复荷载,对比分析了两种节点的滞回性能和耗能能力。最后,以16层立体停车结构为例,分别建立采用耗能节点和未采用耗能节点的立体停车结构的有限元模型。在罕遇地震作用下,分别对这两种结构整体进行动力时程分析,分析耗能节点对立体停车结构整体抗震性能的影响。结果表明:与角钢节点相比,耗能节点的割线刚度、屈服位移、屈服荷载和极限荷载都有大幅度提高;耗能节点的耗能效果要远优于角钢节点;罕遇地震下耗能节点对结构基底剪力、速度与加速度有很大的控制效果,可以改善立体停车结构的受力和地震响应;罕遇地震下耗能节点并没有对结构刚度造成损失并且对结构的主要受力构件起到很大程度的保护作用。

In order to solve the problem of brittle failure of steel beam-column joints in earthquakes, on the basis of steel beam-column joint connected by angle steel ( hereinafter referred to angle joint), by the way of adding channel steel at beam web and changing the bolt hole into slotted hole, a new kind of beam-column energy dissipation joint ( hereinafter referred to dissipation joint) of steel frame structure is proposed , which dissipating energy by sliding friction. First, the refined FE models of energy dissipation joint and angle steel joint are established using FE software ANSYS, the monotonic static load is applied to the FE models of the 2 kinds of joint, and the force mechanisms, the bending moment-rotation characteristics and the mechanical properties of the 2 kinds of joint are compared and analyzed. Then, the low cyclic repetitive load is applied to the 2 refined FE models, and the hysteretic performance and energy dissipation capacity of the 2 kinds of joint are compared and analyzed. Finally, taking the 16-storey 3D parking structure as an example, the 3D parking structure FE models with and without dissipation joint are set up. Under the rare earthquake, the overall structure dynamic time-history analysis on the 2 kinds structure respectively is conducted to find out the effect of dissipation joint on the overall seismic performance of 3D parking structure. The result shows that (1) the secant stiffness, yield displacement, yield load and ultimate load of dissipation joint are greatly improved compared with angle steel joint;(2) the energy dissipation effect of dissipation joint is much better than that of angle steel joint;(3 ) under the rare earthquake, dissipation joint has great control effect on the base shear force, velocity and acceleration of the structure, which can improve the force and seismic response of the 3D parking structure;(4) the dissipation joint under rare earthquake does not cause structural rigidity loss and plays a significant role in protecting major stressed member of the structure.