抛物线型剪滞翘曲位移函数引起的附加轴力分析  

ADDITIONAL AXIAL FORCE ANALYSIS CAUSED BY PARABOLICAL WARPING DISPLACEMENT ABOUT SHEAR LAG

作　　者：蔺鹏臻[1] 周世军[1] 刘凤奎[1] 

机构地区：[1]兰州交通大学甘肃省道路桥梁与地下工程重点实验室,甘肃兰州730070

出　　处：《工程力学》2010年第8期90-93,119,共5页Engineering Mechanics

基　　金：甘肃省自然科技基金项目(3ZX062-B25-008);兰州交通大学"青蓝"人才工程基金计划项目(QL-06-18A)

摘　　要：该文的目的是分析剪力滞效应计算时假定截面中性轴与形心轴重合而产生的附加轴力及其相对大小。利用截面的静力平衡条件,建立了抛物线型翘曲位移函数下截面附加轴力的表达式,并讨论了附加轴力的基本特点。通过引入附加轴向应力比直观反映附加轴力的相对大小,对典型的简支梁、悬臂梁和连续梁在集中力和均布荷载作用下的附加轴向应力比的数值分析。结果表明附加轴向应力相对较小,对剪力滞效应计算精度的影响在5%以内,对抛物线型翘曲位移函数进行考虑轴力平衡的修正是没有必要的。The purpose of this paper is to analyse the additional axial force and its relative value caused by supposing the neutral axis through the sectional centroid of a cross section of a beam. Based on the balance condition of the cross section, the formula of the additional axial force is presented for a parabolical shear lag warping displacement, and the characters of the additional axial force are discussed. For measuring the value of the additional axial force, the ratio of the additional axial stress is proposed. The ratio of a simple supported, a cantilever and a continuous beam are analyzed under a concentrated load and uniformly distributed loads. The results show that the ratio of additional axial stress of a simple supported beam, a cantilever and a continuous beam are usually less than 5%, therefore the additional axial force has little influence on the precision of stress calculation, and the parabolical shear lag warping displacement has high analysis precision and needless to be revised.

关 键 词：桥梁工程 箱梁 剪力滞 翘曲位移函数 附加轴力 

分 类 号：U448.213[建筑科学—桥梁与隧道工程]