T型方管节点抗火性能的有限元分析

利用有限元程序ABAQUS对高温下恒载作用时T型方管节点的耐火性能进行了分析.有限元模型的精确性通过与有关文献报道的试验结果进行对比得到验证.分析计算时,由于高温引起材料性能衰退,考虑材料非线性以及大变形效应的几何非线性;节点环境温度符合ISO834标准升温曲线;分析方法为间接热力耦合;钢材在高温下的材料性能参数按照在结构抗火方面应用广泛的欧洲规范（Eurocode 3）采用.研究了T型方管节点在不同荷载水平作用下,主管变形、主管端部轴向反力随温度变化的规律,以及临界温度与荷载水平的关系等.

Finite Element Analysis on Fire Resistance of Square Hollow Section T-joint

Fire resistance of square hollow section （SHS） loading level is analyzed by using finite element analysis （ and proved to be reliable from benchmark verification with T-joint at elevated temperature subjected to fixed axial FEA）. Before FEA, finite element model is established reported experimental results. Material nonlinearity and geometric nonlinearity caused by temperature have been taken into consideration in the numerical analysis. In addition, the environmental temperature is consistent with ISO834 standard heating curve and coupled thermal-stress method is used. The steel material parameters at elevated temperature are defined in according with Eurocode 3 which is widely applied in fire-resistant research work of engineering structures. In this study, some conclusions on the fire resistance of SHS T-joint are proposed. It is found that deformation of the chord and reaction force at the chord ends are changed with temperature. Additionally, the relationship between loading ratio and critical temperature is also concluded.