In this paper,we propose a probabilistic method for analysing the collapse time of steel frame structures in a fire.The method considers the uncertainty of influencing factors.Tornado diagrams are used for sensitivity...In this paper,we propose a probabilistic method for analysing the collapse time of steel frame structures in a fire.The method considers the uncertainty of influencing factors.Tornado diagrams are used for sensitivity analysis of random variables.Structural analysis samples are selected by Monte Carlo method,and the collapse times of different structural samples are calculated by fire time history analysis.A collapse time fragility curve is fitted according to the calculated collapse times of the samples.A reliability index of the collapse time is used as a quantitative standard to evaluate the collapse performance of a steel frame in a fire.Finally,this method is applied to analyse the collapse time fragility of an eight-storey 3 D steel frame structure under different compartment fire scenarios and fire protection levels.According to the collapse time fragility curve,the effects of the different fire scenarios and protection levels on the collapse resistance of the structure under fire are evaluated.展开更多
文摘针对组合梁斜拉桥钢混结合段钢格室进行了参数设计及力学性能分析.通过ANSYS建立某大桥钢混结合段的有限元模型,主要讨论了钢承压板的厚度、钢格室的长度、剪力钉和PBL键的间距等设计参数对钢格室性能的影响.计算分析得出钢承压板最佳理论厚度为40～80 mm,钢格室最佳理论长度为2m,剪力钉和PBL键最佳理论间距为150 mm.
基金Project supported by the National Natural Science Foundation of China (No. 51678358)。
文摘In this paper,we propose a probabilistic method for analysing the collapse time of steel frame structures in a fire.The method considers the uncertainty of influencing factors.Tornado diagrams are used for sensitivity analysis of random variables.Structural analysis samples are selected by Monte Carlo method,and the collapse times of different structural samples are calculated by fire time history analysis.A collapse time fragility curve is fitted according to the calculated collapse times of the samples.A reliability index of the collapse time is used as a quantitative standard to evaluate the collapse performance of a steel frame in a fire.Finally,this method is applied to analyse the collapse time fragility of an eight-storey 3 D steel frame structure under different compartment fire scenarios and fire protection levels.According to the collapse time fragility curve,the effects of the different fire scenarios and protection levels on the collapse resistance of the structure under fire are evaluated.
