钢筋混凝土T形梁火灾后残余性能有限元分析  

FINITE ELEMENT ANALYSIS OF RESIDUAL PERFORMANCE OF REINFORCED CONCRETE T-BEAM AFTER THE FIRE

作　　者：魏国海 WEI Guohai(College of Civil Engineering,Qingdao University of Technology,Shandong Qingdao 266033,China)

机构地区：[1]青岛理工大学土木工程学院,山东青岛266033

出　　处：《低温建筑技术》2021年第4期42-45,55,共5页Low Temperature Architecture Technology

摘　　要：高温受火后钢筋混凝土构件剩余力学性能准确检验,是火灾以后对结构损伤评定与加固设计的基础。通过ANSYS计算总结T形梁不同参数下的残余承载力与变化规律。研究结果表明,通过对高温后T形梁抗弯承载力和抗弯刚度的计算,发现刚度的损失幅度很大,且前30min内损伤更严重,后期损伤幅度逐渐变缓,与刚度变化趋势不同,高温后抗弯承载力损失幅度并不大,这是由于钢筋在恢复到常温后强度也随之恢复,承载力的损失主要是受压区混凝土的损失。通过增加保护层厚度可以减缓受拉钢筋的受热速度,有效的减缓构件的损伤。单独对带裂缝梁的火灾情况进行分析,与不带裂缝的梁进行对比,得出裂缝的存在加速了混凝土梁的损伤速度。Accurate test of residual mechanical properties of reinforced concrete members subjected to high temperature fire is the basis of structural damage assessment and reinforcement design after the fire.The residual bearing capacity and the change rule of T-beam under different parameters under high temperature were calculated by ANSYS.The results show that the loss of the stiffness is more serious in the first 30 minutes than that in the later period.Whereas,the loss of flexural capacity is small,which is mainly due to the strength of steel bars restored to normal temperature as well as the contribution of compression zone concrete.Additionally,the heating speed of the tensile steel bar could be slowed down,resulting in effectively slow damage of the member by increasing the thickness of the protective layer.Finally,the fire of beam with cracks is separately analyzed and compared with the beam without cracks,concluding that the existence of cracks accelerates the damage velocity of concrete beam.

关 键 词：T型梁 数值模拟 刚度 承载力 

分 类 号：TU352.5[建筑科学—结构工程]