火灾升降温及灾后全过程网架结构力学性能分析

建立了考虑升降温和火灾后网架力学性能分析的有限元模型,并对网架的变形模式、应力重分布规律和火灾后的破坏方式进行了研究.分析表明,升降温过程中网架出现了明显的应力重分布和残余应力,火灾后加载时网架出现了明显拉力膜效应,受火后部分杆件由于受冷收缩,拉力增加,可能引起网架的破坏,在火灾后的修复加固中应予以注意.

Mechanical Behavior of Spatial Grid Structures During Heating and Cooling and After Fire

A finite element model analyzing the fire performance of grid structures during heating and cooling and after fire is proposed in the paper,and the deformation mode,the stress redistribution,the failure mode of grid structures are also studied.The results shows that evident stress redistribution and residual stress occur during heating and cooling,and tensile membrane action arises when the space grids is loaded after fire.Tensile internal forces in several truss members may increase,and causing failure of the grid structures,this should be sepcially noticed in structural repairings.