钢结构端板连接梁柱结点抗火性能试验和有限元分析

Experimental Research and Finite Element Analysis on the Fire-Resistance Performance of Joints of End-Plate Connection in Steel Structure

目的研究端板连接梁柱结点抗火性能,给出端板连接梁柱节点的合理构造措施,为其抗火设计提供理论依据.方法采用全尺寸火灾试验对端板连接梁柱结点的关键部位及最大失效荷载进行研究,在此基础上利用ANSYS有限元分析软件对梁柱结点进行不同工况下的数值模拟,并与试验结果进行比较.结果建立了不同温度下的荷载-位移曲线,为了保证结构在高温下的延性,应避免端板连接处的螺栓和焊缝过早破坏;当温度超过550℃时,端板与螺栓接触的部分易发生受剪及受拉破坏,导致结构倒塌.结论在斜向拉力作用下,端板与梁腹板连接的部分为危险区域,易发生破坏.工程中,为了保证梁柱火灾下的稳定性,防止结构垮塌,建议设置加劲肋.

In order to provide a theoretical basis and a reasonable structure form for fire resistance design,the fire-resistance performance of end-plate joints in steel structure w as studied. The key parts and the failure load of end-plate connection joints w ere studied through the full scale fire test,and beam-column joints w ere simulated under different w orking conditions using the finite element analysis softw are ANSYS. Simulation results w ere compared w ith the experimental results.The load-displacement curves under different temperatures w ere obtained. It founds that in order to ensure the ductility of structure under elevated temperatures,the premature failure of fillet w eldsand bolts in end-plate connections should be avoided. When the temperature exceeds 550℃,the tensile and shear failures in the contact parts of bolts and end-plate are easy occur and can lead to structural collapse. Conclusion is that the connection parts of end-plate and beam w eb are dangerous zones. To guarantee the stability of structure under fire,the stiffening ribs should be used in engineering to prevent structural collapse.