中南大学学报（自然科学版）2025，Vol.56Issue(2)：622-636,15.DOI:10.11817/j.issn.1672-7207.2025.02.018
钢框架在火灾和爆炸联合作用下的破坏倒塌机理
Collapse mechanism of steel frames under combined action of fire and explosion
摘要
Abstract
The collapse mechanism of steel frames under the combined action of fire and explosion was studied by establishing a finite element model of a 5-storey,2-span steel frame using ANSYS/LSDYNA.The temperature distribution characteristics and structural response of the steel frame under the single action of fire were analyzed using an implicit analysis method.Subsequently,the steel constitutive model considering the effect of high temperature and high strain rate was verified through finite element method.Based on reliable results,the explicit analysis method was used to analyze individual explosions as well as the combined action of fire and explosion on the steel frame,obtaining local failure characteristics and overall responses at different fire burning times and under explosion conditions.The results indicate that the elastic modulus and yield strength of steel will deteriorate when exposed to fire,leading to the destruction of the column if subjected to a load exceeding its ultimate bearing capacity at high temperatures.The longer the duration of the fire,the higher the temperature of the components,resulting in an increased susceptibility for collapse of the steel frame.Additionally,at equivalent temperatures,there is greater damage to web-facing surfaces compared to flange-facing surfaces when exposed to blast.In a single-room fire,the explosion occurs at the edge central column where the steel frame has the worst resistance to collapse,while at the central column the steel frame has the strongest resistance to collapse,and at the corner column,the steel frame's resistance to collapse is between the two.In adjacent double-room and four-room fires,an explosion occurs at the central column,causing the concrete slab above the fire room to collapse due to shear failure of the beams below.In a diagonal double-room fire,an explosion occurs at the central column,causing the steel frame to collapse as the central column and edge central column fail successively.关键词
火灾/爆炸/钢框架/有限元分析/连续倒塌Key words
fire/blast/steel frame/finite element analysis/progressive collapse分类
土木建筑引用本文复制引用
田力,王剑飞..钢框架在火灾和爆炸联合作用下的破坏倒塌机理[J].中南大学学报（自然科学版）,2025,56(2):622-636,15.基金项目
国家自然科学基金资助项目(51238007,51178310)(Projects(51238007,51178310)supported by the National Natural Science Foundation of China) （51238007,51178310）
