不同翘曲位移函数对薄壁箱梁剪力滞效应的影响  

Influence of Different Warping Displacement Functions on Shear Lag Effect of Thin-walled Box Girders

作　　者：黄洪猛 张元海[1] HUANG Hong-meng;ZHANG Yuan-hai(School of Civil Engineering,Lanzhou Jiaotong University,Lanzhou730070,China;School of Civil Engineering,Northwest Minzu University,Lanzhou730030,China)

机构地区：[1]兰州交通大学土木工程学院,兰州730070 [2]西北民族大学土木工程学院,兰州730030

出　　处：《兰州交通大学学报》2022年第3期1-7,13,共8页Journal of Lanzhou Jiaotong University

基　　金：国家自然科学基金(51968040,51468032);甘肃省高等学校创新基金(2021B-068)。

摘　　要：为了评价不同翘曲位移函数对薄壁箱梁剪力滞效应的影响,以剪力滞引起的附加挠度来描述纵向翘曲位移,选取了不同幂次抛物线、余弦曲线、悬链线等形式的翘曲位移函数,并对其多参数修正,应用能量变分法推导剪力滞控制微分方程并求得解析解.引入表征解析解与有限元解吻合程度的均方根误差,结合简支箱梁和两跨连续箱梁等算例进行分析,结果表明:按多参数修正后的不同翘曲位移函数计算的箱梁顶底板峰值应力均与有限元解吻合良好;根据均方根误差值,顶板按余弦曲线、二次抛物线或悬链线计算的应力总体差异较小,且与有限元解总体吻合良好,跨中截面和中支承截面的底板分别按五次抛物线、三次抛物线计算的应力与有限元解总体吻合良好;不同翘曲位移函数计算的附加挠度差异明显,但对计入初等梁挠度后的总挠度影响很小.In order to evaluate the influence of different warping displacement functions on the shear lag effect of thin-walled box girders,the additional deflection induced by shear lag was adopted to describe the longitudinal warping displacement,the parabola with different powers,cosine curve,and catenary with multi-parameter modification were selected as the warping displacement function,respectively.The shear lag governing differential equation were derived by energy variational method and the analytical solutions were obtained.The root mean square error,which represents the degree of agreement between the analytical solution and the finite element solution,was introduced to analyze the results with examples such as simply supported box girder and two-span continuous box girder.The results show that the peak stresses at the top and bottom slabs calculated by different warping displacement function with multi-parameter modification are all in good agreement with that by finite element method.The stresses in the top slab calculated by cosine curve,quadratic parabola and catenary show little difference on the whole,which agree well with those by finite element method.The stresses in the bottom slab at mid-span and mid-supported cross section calculated respectively by the fifth parabola and the cubic parabola agree well with those by finite element method.The additional deflection calculated by different warping displacement functions is obviously different,but it has little effect on the total deflection.

关 键 词：薄壁箱梁 剪力滞效应 能量变分法 翘曲位移函数 附加挠度 均方根误差 

分 类 号：U448.213[建筑科学—桥梁与隧道工程]