火灾下混凝土结构破坏模拟的纤维梁单元模型  

Firer beam element model for the collapse simulation of concrete structures under fire

作　　者：陈适才[1] 陆新征[1] 任爱珠[1] 江见鲸[1] 

机构地区：[1]清华大学土木工程系,北京100084

出　　处：《计算力学学报》2009年第1期72-79,共8页Chinese Journal of Computational Mechanics

基　　金：国家"十一五"科技支撑计划(2006BAK01A02-09);清华大学基础研究基金(JC2007003)资助项目

摘　　要：为分析和模拟结构构件在火灾下的失效破坏过程,本文基于建筑结构分析中常用的纤维梁单元模型,建立了钢筋混凝土梁、柱构件的火灾破坏数值模型。此模型将构件截面划分成多个纤维,从而可以模拟构件截面的不均匀温度场分布以及高温下混凝土材料的开裂、压碎和钢筋屈服等行为。并根据全拉格朗日描述方法,推导了纤维梁单元的切线刚度矩阵,建立了纤维梁单元的增量求解方程。最后,将本文模型的模拟结果和多个具体试验结果进行了分析比较,进一步验证了模型的可靠性。In order to analyze and simulate the collapse of reinforced concrete （RC） elements under fire, a novel numerical model based on the fiber beam model is proposed in this paper. By dividing the cross section of RC beam element into many small concrete and steel fibers and assigning different materials to each fiber, this model can consider the non-uniform temperature distribution across the section and simulate the behavior of cracking or crushing for concrete and yielding for steel. The material stress-strain relationship at high temperature of each fiber is based on the model proposed by EuroCode 2. The explicit tangential stiffness matrix is deduced for proposed fiber beam with total Lagrange description, and the incremental equilibrium equations are also established. Finally, the fiber model proposed in this paper is validated by comparing with various experimental results.

关 键 词：纤维模型 梁单元 火灾反应 非线性 

分 类 号：TU375[建筑科学—结构工程]