薄壁箱梁剪力滞翘曲位移函数的改进与对比分析  

An improvement and comparative analysis of shear lag warping displacement function in thin-walled box girder

作　　者：张玉平[1] 胡火全 李传习[1] 陈洪林[1,2] 

机构地区：[1]长沙理工大学土木与建筑学院省部共建教育部"桥梁工程安全控制"重点实验室,长沙410004 [2]湖南省高速公路管理局,长沙410016

出　　处：《应用力学学报》2016年第6期1099-1105,1126,共7页Chinese Journal of Applied Mechanics

基　　金：国家自然科学基金(51378080);科技部973项目(2015CB057702);长沙理工大学土木工程优势特色重点学科创新性项目(15ZDXK02)

摘　　要：基于能量变分原理,考虑箱梁横截面正应力轴向平衡条件和剪切变形的影响,构建了包含参数m的新剪力滞翘曲位移函数。以所得应力均方误差与挠度均方误差为精度标准,计算分析了不同m值(即不同幂次)抛物线下新构建剪力滞翘曲位移函数的适应性,得出了二次抛物线形式较为精确合理的结论。通过比较典型位置所得应力值,进一步分析了新构建剪力滞翘曲位移函数(m=2)的适应性和精确性。针对所得集中荷载作用下简支箱梁翼缘悬臂板最外端应力有较大偏差的情况,通过应力曲线拟合,得到了集中荷载作用下简支箱梁悬臂板的应力改进公式。将应力改进后新构建剪力滞翘曲位移函数与基本翘曲位移函数所得的应力与竖向挠度进行比较,论证了通过本文新构建的剪力滞翘曲位移函数推导计算所得的应力公式和应力改进公式的高精度。Based on the energy variational principle, taking into account the normal stress equilibrium condition in axial cross-section and shear deformation of box girder, a new shear lag warping displacement function that contains parameter m is established. In this paper, the calculated mean square errors of stress and deflection are taken as standards to analyze the adaptabilities of the new functions with different parameter m. The conclusion shows that the quadratic function is more accurate. Through comparing the calculated stresses in typical sections, furthermore, the accuracy and adaptability of the new function(m=2) is analyzed. When determining the stress of the outermost tip of the flange in a simply supported box girder under concentrated load, there is a certain deviation in the calculation results. To eliminate the deviation, a new improved formula is given by stress curve fitting. Meanwhile, the stresses and deflections calculated by the newly established shear lag warping displacement function and the basic function are compared with traditional ones, respectively, to prove its validity and high calculation accuracy.

关 键 词：桥梁工程 剪力滞翘曲位移函数 能量变分法 薄壁箱梁 抛物线 

分 类 号：U448.213[建筑科学—桥梁与隧道工程]