工字形曲线组合梁负弯矩区侧向失稳分析  

Lateral Buckling Analysis of I-curve Composite Beams in Negative Moment Region

作　　者：陈百玲[1] 李明姝 刘文文 王连广[1] CHEN Bailing;LI Mingshu;LIU Wenwen;WANG Lianguang(School of Resources&Civil Engineering,Northeastern University,Shenyang,China,110819)

机构地区：[1]东北大学资源与土木工程学院,辽宁沈阳110819

出　　处：《沈阳建筑大学学报（自然科学版）》2021年第4期586-593,共8页Journal of Shenyang Jianzhu University：Natural Science

基　　金：国家自然科学基金青年基金项目(51808100);辽宁省自然科学基金指导计划项目(2019-ZD_0004);辽宁省自然科学基金项目(20170540303)。

摘　　要：目的为曲线组合梁结构设计提供理论依据,研究负弯矩区工字形曲线组合梁考虑上、下翼缘均发生侧向弯曲变形与扭转变形的稳定性。方法基于能量法推导等端弯矩作用下曲线钢梁上、下翼缘及混凝土板应变能,基于势能驻值定理推导曲线组合梁侧向失稳临界弯矩解析解。分析比较不同参数对临界弯矩的影响。结果曲率半径从4000 mm增加到8000 mm,临界弯矩增加了18.5%。底板宽厚比由9增加到17,临界弯矩增加了一倍;混凝土板厚度由120 mm增加到160 mm,临界弯矩增加了19.1%;钢筋数量由8根增加到16根,临界弯矩增加了8.9%;腹板高厚比由25增加到37,临界弯矩降低了40%。随着跨度的增加,临界弯矩整体趋势逐渐减小但曲线存在回弹。结论临界弯矩受腹板高厚比、底板宽厚比和曲率半径的影响较大,可结合工程实际通过增大曲率半径和底板宽厚比或减小腹板高厚比来控制侧向失稳临界弯矩。The lateral buckling in the negative moment region of I-curved composite beam considering the lateral bending deformation and torsional deformation of the upper and bottom flange of the steel beam was analyzed.Based on the energy method,the strain energies of the upper and lower flanges of curved steel beams and concrete plates under the action of equal end bending moments was derived.Based on the standing value theorem of potential energy,the analytical solution of critical moment for lateral instability of curved composite beams was derived.The influence of several design parameters on the critical bending moment was analyzed and compared.The curvature radius increases from 4000 mm to 8000 mm,the critical bending moment increases by 18.5%.The width-thickness ratio of the bottom plate increases from 9 to 17,the critical bending moment doubled.The concrete slab thickness increases from 120 mm to 160 mm,the critical bending moment increases by 19.1%.The amount of reinforcement increases from 8 to 16,the critical bending moment increases by 8.9%.The web height-thickness ratio changed by 12,the critical bending moment decreased by 40%.The overall trend of critical bending moment of curved composite beams decreases gradually with the increase of span,but the curve bounces.The critical moment can be well controlled by increasing curvature radius and the width-thickness ratio of the bottom plate or decreasing the web height-thickness ratio,which provides data support for the structural stability design of I-curved composite beams.

关 键 词：负弯矩区 工字形曲线组合梁 能量法 侧向失稳 临界弯矩 

分 类 号：TU398[建筑科学—结构工程]