初始残余应力对预应力钢-混凝土连续组合梁抗火性能影响  

Effect of initial residual stress on fire resistance of prestressed steel-concrete continuous composite beams

作　　者：周焕廷[1] 郑志远 陈志华[1] ZHOU Huanting;ZHENG Zhiyuan;CHEN Zhihua(School of Civil Engineering and Architecture,Wuhan University of Technology,Wuhan 430070,China;China Construction Third Bureau Green Industry Investment Co.,Ltd.,Wuhan 430100,China)

机构地区：[1]武汉理工大学土木工程与建筑学院,湖北武汉430070 [2]中建三局绿色产业投资有限公司,湖北武汉430100

出　　处：《建筑结构学报》2022年第5期130-139,148,共11页Journal of Building Structures

基　　金：国家自然科学基金项目(51878528)。

摘　　要：为研究钢梁残余应力对预应力连续组合梁抗火性能的影响,建立了预应力连续组合梁在高温下非线性升温过程受力行为的有限元模型。通过考察梁的破坏形式、跨中挠度、预应力拉索张力、截面弯矩以及梁的曲率等关键参数随温度的变化,得到不同残余应力模式对组合梁抗火性能的影响机理。分析结果表明:残余应力的分布并不总是对预应力钢-混凝土组合梁的高温性能产生不利影响,腹板具有初始残余拉应力分布模式的预应力钢-混凝土组合梁高温下的挠度相对最小;残余应力主要通过影响截面正应力分布来影响钢梁的截面刚度;在临界状态时,残余应力对组合梁截面刚度的影响不明显;不同残余应力模式对高温下预应力钢-混凝土组合梁的截面抗弯刚度影响不同;当预应力钢-混凝土组合梁的初始残余应力模式以腹板全截面拉应力为主时,预应力钢-混凝土组合梁跨中截面抗弯刚度最大;当残余应力对组合梁跨中截面抗弯刚度有利时,梁跨中截面处中和轴位置比无残余应力影响时较高。To study the effect of residual stress on fire resistance of prestressed continuous composite beams,nonlinear finite element models of prestressed continuous composite beams under high temperature were established.The influence mechanism of different residual stress modes on the fire resistance of composite beams was obtained by investigating the changes of failure modes,mid-span deflections,pretension in cable tension,sectional bending moments and beam curvatures with temperature.The results demonstrate that the initial residual stress does not always have negative effect on the fire performance of prestressed steel-concrete composite beams.The initial residual distribution mode with tensile stress in the web decreases the deflection of prestressed steel-concrete composite beams at high temperature.The residual stress mainly affects the sectional flexural stiffness of steel beam by affecting the longitudinal stress distribution of the cross-section.In the critical state,the residual stress has little effect on the sectional stiffness of composite beams.Different residual stress modes have different effects on the flexural stiffness of prestressed steel-concrete composite beams at high temperature.The flexural stiffness of mid-span section of prestressed continuous steel-concrete composite beams at high temperature is maximum when the mode of initial residual stress makes the web bear tensile stress.When the residual stress contributes to the bending stiffness of the mid-span section of the composite beam,the height of neutral axis position at the mid-span section of the beam is higher than that at the mid-span section without residual stress.

关 键 词：钢-混凝土组合梁 预应力 有限元分析 残余应力 抗火性能 

分 类 号：TU398.9[建筑科学—结构工程] TU311.41