槽钢加强钢梁腹板开圆孔梁柱节点滞回性能数值模拟分析

Numerical simulation analysis of hysteresis behavior of beam-column joints with circular holes in the steel beam web reinforced with channel steel

为解决钢梁腹板开圆孔型节点开孔处抗震承载力不足、受力变形过大等问题,提出了在钢梁腹板孔洞区域设置开孔槽钢的加强方法,并以槽钢弧形削弱位置rl、削弱深度c、槽钢厚度t、槽钢材性m为主要参数,设计了15个节点模型。运用有限元软件ANSYS模拟分析了循环荷载作用下各模型的滞回曲线、骨架曲线、刚度退化情况及耗能能力。结果表明:在梁腹板开孔处设置槽钢后,节点的极限承载能力、初始刚度、耗能能力较未加强节点均大幅度提升;槽钢上下翼缘及腹板进行适当弧形削弱的节点较未削弱或削弱不当的节点,其后期刚度退化速率较小,滞回曲线更加饱满,总能量耗散系数最大;槽钢削弱位置rl和削弱深度c相同的节点的承载力、初始刚度、耗能性能均随着槽钢厚度t的增加而增加;槽钢的强度等级高于钢梁强度时,节点在峰值位移阶段的耗能能力显著降低。

In order to solve the problems of insufficient seismic bearing capacity and excessive deformation at the opening of steel beam web circular hole type joint,the strengthening method of setting opening channel steel in the hole area of steel beam web was proposed.With the arc weakening position rl,weakening depth c,channel steel thickness t and channel steel material m as the main parameters,15 joint models were designed.The hysteretic curve,skeleton curve,stiffness degradation and energy dissipation capacity of each model under cyclic load were simulated and analyzed by using the finite element software ANSYS.The results show that the ultimate bearing capacity,initial stiffness and energy dissipation capacity of the joint are greatly improved after setting the channel steel at the opening of the beam web compared with those of the unreinforced joint;the specimens with appropriate arc weakening of the upper and lower flange and web of the channel steel have smaller stiffness degradation rate,fuller hysteretic curve and the largest total energy dissipation coefficient.The bearing capacity,initial stiffness and energy dissipation performance of the joints with the same channel weakening position rl and weakening depth c increase with the increase of channel steel thickness t.When the strength grade of channel is higher than that of steel beam,the energy dissipation capacity of the joints in the peak displacement stage decreases significantly.