肋板加强型节点空间钢框架抗震性能研究

Study on seismic performance of space steel frame with rib-reinforced joints

针对肋板加强型节点和普通节点空间钢框架的抗震性能,采用ANSYS有限元分析软件对比分析了两种钢框架的破坏形态、承载力、滞回性能、变形能力、耗能能力以及退化性能.研究结果表明,肋板加强型节点可使梁端塑性铰外移至远离梁柱连接焊缝的梁上,避免梁端应力集中导致焊缝发生脆性破坏;肋板加强节点钢框架的极限承载力、等效黏滞阻尼系数与普通钢框架相比有明显提高,进入屈服阶段后由于应力重分布及肋板参与耗能,其刚度及承载力退化速度明显低于普通节点钢框架,肋板加强节点钢框架具有明确的梁铰延性破坏机制,抗震性能更好,推荐在强震区使用.

To examine the seismic performance of the common joint steel frame and the rib-rein- forced joint steel frame, this paper makes a comparative analysis of two kinds of steel frame in failure modes, bearing capacity, hysteretic behavior, deformation, energy dissipation and degradation capacity by the finite element analysis software ANSYS. The analysis shows that the rib-reinforced joint can let the plastic hinge away from the welded connection of beam-column and avoid welded connection brittle fracture induced by the tie-beam stress concentrador~ The ultimate bearing capacity and the equivalent viscous damping ratio of the rib-reinforced joint steel frame is obviously greater than the common joint steel frame. When the steel frame enters the yield stage, the stiffness and bearing degradation of the rib-reinforced joint steel frame is more slower for the stress redistribution and the energy dissipation by the ribs. The fib-reinforced joints steel frame has a clear and ductile beam-hinge failure mechanism. The seismic performance proves to be better, and therefore it is proposed to be used in the meizoseismal areas.