火灾作用下单层球面网壳结构的整体性能分析

基于高大空间建筑火灾下的空气升温实用公式,按照欧洲规范规定的火灾高温下钢材的材料特性,考虑了温度对钢材特性的影响以及钢材屈服后的强化特征,对一凯维特单层网壳结构火灾下的性能进行了非线性有限元分析,研究其在不同局部火灾作用下的温度场分布和位移特征以及不同火源影响的最不利位置.结果表明:大多数设计火源模型下网壳结构的极限耐火时间都小于2 h;火源高度对网壳结构极限耐火时间的影响最大,其次是火源位置,再次是火源面积;结构中心向外延伸的第1环到第3环之间的区域是结构抗火的薄弱部位.

Overall Performance Analysis of Single Layer Reticulated Dome Under Fire

Based on the utility temperature elevation empirical formula in large space fire,the nonlinear finite element analysis of the fire performances on a single layer reticulated dome is numerically simulated with the thermal parameters specified in the EUROCODE 3 and the stress-strain relationship allowing for strain-hardening of steel.The temperature fields,displacement properties of the structure and most unfavorable position are studied under local fire.Based on the nonlinear finite element analysis,the results show that most of the ultimate fire-resistant duration are less than 2 h under different local fires;the influence of the fire height is the biggest on the ultimate fire-resistant duration of the structure,and the effect of the fire location is bigger than the area of the fire;and the region between the first ring and the third ring is the most unfavorable position of the single layer reticulated dome under fire.