火灾对钢筋混凝土简支梁破坏形式的影响  

Effect of fire on failure form of reinforced concrete simply supported beam

作　　者：张峥 ZHANG Zheng(School of Civil Engineering,Shandong Jianzhu University,Jinan 250101,China)

机构地区：[1]山东建筑大学土木工程学院,济南250101

出　　处：《计算机辅助工程》2022年第4期69-74,共6页Computer Aided Engineering

摘　　要：为评估钢筋混凝土梁火灾后的力学性能,采用Abaqus软件模拟钢筋混凝土简支梁三面受火的温度场,利用简化计算公式分析火灾后梁的极限承载力,根据不同影响因素设计多个试件,分析简支梁的破坏特征及破坏形式变化的临界点。结果表明:建立的有限元模型能够较好地模拟高温后钢筋混凝土梁的破坏特征;随着受火时间的增加,试件破坏形式由受剪破坏逐步转变为受弯破坏;随着混凝土保护层厚度及混凝土强度等级的增加,构件由受剪破坏转为受弯破坏的临界点发生明显滞后,其中混凝土强度等级对临界点滞后的影响尤为明显。To evaluate the mechanical properties of reinforced concrete beams after fire,the temperature field of reinforced concrete simply supported beams standing fire on three sides are simulated using Abaqus software,and the ultimate bearing capacity of beams after fire is computed using simplified formula.Several specimens are designed according to the different influencing factors,and the failure characteristics and the critical point of failure form change of the simply supported beams are analyzed.The results show that the finite element model can correctly simulate the failure characteristics of the reinforced concrete beams after high temperature;with the fire exposure time increasing,the failure mode of the specimen gradually changes from shear failure to flexural failure;with the increasing of concrete cover thickness and concrete strength grade,the critical point of specimen failure mode changes from shear failure to flexural failure is obviously delayed,and the concrete strength grade has especiall effect on the delay of the critical point.

关 键 词：钢筋混凝土 简支梁 温度场 剩余承载力 耐火 全过程仿真 

分 类 号：TU375.1[建筑科学—结构工程] TB115.1[理学—数学]