半刚性连接钢框架关键柱破坏后动力响应分析

Dynamic Response Analysis of Semi-Rigid Steel Frame with a Key Column Destroyed

框架中关键柱破坏后,节点的连接刚度将会影响剩余结构的内力重分配及动力响应。建立了9层Benchmark钢结构模型,以端部约束系数r为参数,采用拆除构件法对关键柱破坏后结构体系的动力响应进行了分析,同时分析了不同位置柱破坏对结构体系的影响。分析结果表明:与失效柱相连处的梁其靠近失效点的梁端弯矩随节点连接刚度的增加并无明显变化规律,远离失效点的梁端弯矩随节点连接刚度的增加而增大;与失效柱相连处的梁中轴力随节点连接刚度增大而急剧减小,节点连接刚度大于一定值时,梁中轴力变化不明显;节点连接刚度的提高可以减小结构中关键构件的内力及变形,提高结构的抗倒塌能力。

If a key column fails in a frame, the redistribution of internal forces and dynamic responses will be affected by connection stiffness. A 9-story Benchmark model is created and the Alternate Path Method is adopted to perform the dynamic response of the structure with a key column destroyed. The influence of fixity factor and the effect of destroyed column position are analyzed. The results show that the moment on the end near the failure point of the beam connected to the destroyed column changes irregularly with the increase of connection stiffness while the moment on the end remote to the failure point of the beam increases with the increase of connection stiffness. The axial force in the beam connected to the destroyed column decreases rapidly with the increase of connection stiffness. While the connection stiffness is over a certain value,the axial force changes a little. The increase of connection stiffness results in the decrease of internal force and deformation of the key component in structures and therefore improves the progressive collapse resistance of structures.