由于火灾高温导致钢材弹性模量减小,单层网壳结构在火灾下更容易发生整体失稳现象,为了获得火灾下K8型单层网壳弹塑性稳定承载力计算方法,分析了单层网壳结构火灾高温下有限元计算的原理,对K8型单层网壳结构在整体不均匀温度场和局部高温两种典型火灾升温情形下的弹塑性稳定承载力进行了系统的计算分析和对比,并在此基础上,借鉴常温下K8型单层网壳火灾下弹塑性稳定承载力的计算表达式,得到了火灾下弹塑性稳定承载力的具体计算公式.
The elasticity modulus of steel will decrease with the rise of temperature due to fire,and it's much easier to have global buckling phenomenon for reticulated shells.In order to obtain elasto-plastic stability bearing capacity calculation method for signle-layer reticulated shells,FEA principles for calculating single-layer reticulated shells under fire conditions were discussed,and then,large numbers of numerical simulation models were established to give systematic analysis on the two typical cases which include global non-uniform temperature distribution and localized high temperature for K8 type shells.The calculation formula for calculating elasto-plastic bearing capacity for K8 single-layer reticulated shells is obtained.