空间钢框架连续倒塌拟静力试验

Quasi-static experimental research on progressive collapse of space steel frames

为考察钢框架结构中一根框架柱失效后,剩余结构在倒塌过程中的受力和变形情况,采用MTS和千斤顶配合的方法对二层空间钢框架结构进行了拟静力试验。试验结果显示,在倒塌过程中,框架梁的受力方式从受弯为主向受拉为主转变,当竖向位移达到200mm时,失效区域部分框架梁全截面受拉;当竖向位移接近250mm时,梁柱连接节点处焊缝发生断裂。目前应用比较广泛的H型钢全焊接刚性连接节点延性不够好,在梁形成明显的悬链线效应之前即发生破坏。采用显式动力法以准静态的加载方式对试验过程进行了模拟,建议在对含有H型钢全焊接刚性连接节点的钢框架结构进行连续倒塌分析时,采用较精确的节点模型以真实反应节点的受力。

;The quasi-static experiment on a space steel frame with 2 storeys is carried out with mechanical testing ＆ simulation （MTS） and lifting jack in order to investigate the changes of the internal force and displacement during the collapse process of the remainder structure as a result of a failed column. According to the experimental results, the bearing pattern of the beams suffered a transformation from bending to tension during the collapse process. The cross section of the several beams in the destroyed area is totally in tension when the vertical displacement reached 200ram, and the weld of the beam-column joint fractured at a displacement of 250ram. The ductility of the all-welded rigid connection of the H section structural el- ements which are extensively used in practice is not high enough to generate the notable catenary effect. The quasi-static experiment is simulated by explicit dynamic analysis method in abaqus, and it is necessary to simulate the actual status of the joint using elebrate joint model when carrying out progressive collapse analysis.