基于不同广义位移的薄壁箱梁剪力滞效应分析  

Analysis of Shear Lag Effect in Thin-walled Box Beams Based on Different Generalized Displacements

作　　者：段燕娥 陈超 王方旭 DUAN Yan’e;CHEN Chao;WANG Fangxu(Department of Surveying,Mapping and Geographic Information,Gansu Vocational College of Architecture,Lanzhou 730050,China;School of Civil Engineering,Lanzhou Jiaotong University,Lanzhou 730070,China)

机构地区：[1]甘肃建筑职业技术学院测绘地理信息系,兰州730050 [2]兰州交通大学土木工程学院,兰州730070

出　　处：《科技和产业》2024年第19期324-329,共6页Science Technology and Industry

摘　　要：为了分析基于不同广义位移下剪力滞效应的状态,分别选取翼缘板最大剪切转角差和剪力滞产生的附加挠度作为广义位移,利用能量变分法推导出基于不同广义位移下的箱梁在跨中集中荷载作用下相应的剪力滞系数和应力。引入ANSYS软件建立箱梁有限元模型,结合典型简支箱梁算例进行分析。研究表明:基于不同广义位移所求得的简支箱梁各关键点处的应力值和剪力滞系数与ANSYS值吻合良好,并且基于附加挠度所求得的实际应力值与ANSYS值更为接近;在顶板中点处按选取附加挠度计算的剪力滞系数为0.846,比按选取最大剪切转角差计算的剪力滞系数0.610增大了38.69%;在底板中点处按选取附加挠度计算的剪力滞系数为0.799,比按选取最大剪切转角差计算的剪力滞系数0.610增大了30.98%。In order to analyze the state of shear lag effect under different generalized displacements,the maximum shear angle difference of the flange plate and the additional deflection generated by shear lag were selected as the generalized displacements.The energy variational method was used to derive the corresponding shear lag coefficients and stresses of the box beam under concentrated load at the mid span based on different generalized displacements.ANSYS software was introduced to establish the finite element model of the box beam.The analysis of typical simply supported box girder examples shows that the stress values and shear lag coefficients at key points of the simply supported box girder obtained based on different generalized displacements are in good agreement with ANSYS values,and the actual stress values obtained based on additional deflections are closer to ANSYS values.The shear lag coefficient calculated by selecting additional deflection at the midpoint of the top plate is 0.846,which is 38.69%higher than the shear lag coefficient calculated by selecting the maximum shear angle difference of 0.610.The shear lag coefficient calculated by selecting additional deflection at the midpoint of the bottom plate is 0.799,which is 30.98%higher than the shear lag coefficient calculated by selecting the maximum shear angle difference of 0.610.

关 键 词：薄壁箱梁 广义位移 能量变分法 剪力滞效应 有限元 

分 类 号：U448.213[建筑科学—桥梁与隧道工程]