多高层钢结构耐火性能的子结构分析模型与分析方法

基于整体钢结构在局部火灾下的反应规律,将高层钢结构的初始倒塌破坏类型进行了分类(中间柱初始倒塌、边柱初始倒塌以及梁柱同时倒塌),根据整体结构约束影响和荷载影响,提出局部火灾下多高层钢结构耐火性能分析的相应子结构分析模型及其分析方法。子结构模型的边界充分考虑周围约束的影响,尤其是周围梁和上层柱构件以及层数的影响。针对不同类型的子结构模型,通过建立相应的具体子结构有限元模型,合理考虑边界条件的影响。最后基于建立的数值模型,研究了子结构的火灾反应规律与破坏机理,并与整体结构的分析结果进行了比较,结果表明:子结构分析模型与分析方法可以合理准确地分析整体结构的耐火性能。

Sub-structure Models and Analysis Method for Multi-story Steel Frame Structures under Fire

Based on the fire behavior of steel structures subjected to local fire,the collapse mechanism of buildings initiated by the localized fire can be classified as: interior column buckling,exterior column buckling and interactive failure.Corresponding sub-structure analysis models,taking the effect of loading and constraint into account,are introduced to analyze the performance of steel structures under fire.The constraint boundary conditions such as the neighboring beams,columns and the surrounding floors are considered.Finite element models are developed to simulate the fire response of the substructure.Results obtained by proposed models are compared with those of the monolithic steel structure.It is shown that the sub-structure analysis models are feasible to simulate and assess the performance of multi-story steel structures under fire.