边界约束条件对箱形梁畸变效应的影响  

Influence of boundary restraint condition on distortion effect of box girders

作　　者：王妍 张元海[1] 王晨光[1] WANG Yan;ZHANG Yuanhai;WANG Chenguang(School of Civil Engineering,Lanzhou Jiaotong University,Lanzhou 730070,China)

机构地区：[1]兰州交通大学土木工程学院,甘肃兰州730070

出　　处：《中南大学学报（自然科学版）》2021年第12期4475-4483,共9页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(51968040,51468032)。

摘　　要：为了分析不同边界约束条件对箱形梁畸变效应的影响,选取畸变中心处直角的改变量为基本未知量,用能量变分法建立畸变控制微分方程,导出梁端边界条件分别为简支和固定相组合的箱形梁在竖向偏心均布荷载作用下的畸变效应解析解。以简支箱梁为基准,通过引入畸变效应边界影响系数,结合数值算例详细分析不同边界及截面几何参数对箱形梁畸变效应的影响。最后采用有限元软件ANSYS对本文解析解进行验证。研究结果表明:本文解析解的计算结果与ANSYS壳单元计算结果吻合良好;梁端约束程度越高,畸变效应纵向分布曲线越陡峭;高宽比越大,畸变效应边界影响系数越小;当截面几何参数变化时,边界约束条件对畸变角的影响较小;当高宽比取1.06且悬臂板相对宽度大于0.25时,边界约束条件对箱形梁畸变翘曲正应力的影响较小。In order to analyse the influence of different boundary restraint conditions on distortion effect of box girders,the variation of the right angle at distortion center was selected as the basic unknown and the governing differential equation was established by applying energy variation method.The analytic solution to distortion effect of box girders subjected to vertical eccentric uniform load was derived considering combined boundary restraint condition of simply supported and fixed-end,respectively.Based on the simply supported box girder,the boundary influence coefficient was introduced to analyse the influence of different boundaries and cross-section geometric parameters on distortion effect in detail,combined with a numerical example.The derived analytic solution was verified by using finite element software ANSYS.The results show that the analytic solution are in a good agreement with those by the shell element in ANSYS.The stronger the end restraint,the steeper the longitudinal distribution curve of distortion effect.And the larger the height to width ratio,the smaller the boundary influence coefficient.The boundary constraint condition has little influence on distortion angle when the cross section geometric parameter changes.The boundary constraint condition has little effect on the warping normal stress of box girders when the height to width ratio is 1.06 and the relative width of cantilever slab exceeds 0.25.

关 键 词：箱形梁 畸变效应 能量变分法 边界条件 边界影响系数 

分 类 号：U448.213[建筑科学—桥梁与隧道工程]