变厚度翼缘板箱梁剪力滞分析的有限梁段法  

Finite Beam Segment Method for Shear Lag Analysis on Box Girders with Variable Thickness Flange Plates

作　　者：周世军[1,2] 周操 李贤伟 陈晨 史雨安 汪刚 ZHOU Shijun;ZHOU Cao;LI Xianwei;CHEN Chen;SHI Yu’an;WANG Gang(School of Civil Engineering,Chongqing University,Chongqing 400045,China;Key Laboratory of New Technology for Construction of Cities in Mountain Area,Ministry of Education,Chongqing University,Chongqing 400045,China;Fifth Engineering Co.,Ltd.,China Railway 21st Bureau Group Corporation Limited,Chongqing 402160,China)

机构地区：[1]重庆大学土木工程学院,重庆400045 [2]重庆大学山地城镇建设与新技术教育部重点实验室,重庆400045 [3]中铁二十一局集团第五工程有限公司,重庆402160

出　　处：《铁道学报》2025年第3期142-153,共12页Journal of the China Railway Society

基　　金：重庆市永川区技术创新与应用发展专项重点项目(2021yc-cxfz20004)。

摘　　要：为研究变厚度翼缘板薄壁箱梁的剪力滞效应,提出一种适应不同荷载形式及边界条件下剪力滞分析的有限梁段法。首先通过翼板剪切变形规律定义剪力滞翘曲位移函数,再应用最小势能原理建立剪力滞基本微分方程。在变分原理基础上,提出每节点包含两个剪力滞自由度的梁段单元并对其进行Hermite位移插值,导出考虑剪力滞与梁弯曲刚度耦合影响的单元刚度矩阵。结合具体算例分析箱梁的纵横向剪力滞效应,结果表明:有限梁段法解与实体有限元解和能量变分法解吻合良好且具有较高的精度,验证了方法的准确性和适用性;与通过面积相等将变厚度翼缘板简化成等厚度翼缘板的方法相比,考虑翼缘板厚度变化的方法能够提高计算精度,最大可提高19.3%(悬臂板根部位置)。最后应用有限梁段法对某大跨连续刚构箱梁桥在选定荷载工况下的剪力滞效应进行分析,为复杂桥梁结构中变厚度翼缘板箱梁剪力滞的研究提供了理论基础与经验借鉴。To study the shear lag effect on thin-walled box girders with variable thickness flange plates,a finite beam segment method applicable to shear lag analysis under different load forms and boundary conditions was proposed in this paper correspondingly.Firstly,with the shear lag warping displacement function defined by the shear deformation law of flange plate,the basic differential equation of shear lag was established using the principle of minimum potential energy.Secondly,based on the variational principle,a beam segment element with two degrees of freedom of shear lag at each node was proposed and its displacement was interpolated according to Hermite interpolation function.The element stiffness matrix considering the coupling effect of shear lag and beam bending stiffness was derived.By analyzing the longitudinal and transverse shear lag effect of box girder with specific examples,the results show that the finite beam segment method is in good agreement with the solid finite element method and the energy variational method with high accuracy,verifying the accuracy and applicability of the method.Compared with the method of simplifying the variable thickness flange plate into equal thickness flange plate by equal area,considering the change of flange plate thickness can improve calculation accuracy,with a maximum improvement of 19.3%(at the root of the cantilever plate).Finally,the finite beam segment method was used to analyze the shear lag effect of a long-span continuous rigid frame box girder bridge under selected load conditions,which provides a theoretical basis and experience for the study of shear lag on variable thickness flange plate box girders in complex bridge structures.

关 键 词：箱梁 剪力滞效应 变厚度翼缘板 能量变分法 有限梁段法 

分 类 号：U448.213[建筑科学—桥梁与隧道工程]