荷载横向变位下变截面连续箱梁剪滞分析的有限梁段法

发布时间：2018-08-10 07:10

【摘要】：为研究荷载横向作用位置变化对箱梁剪滞效应的影响,对箱梁顶、底板、悬臂板分别设置了不同的剪滞纵向位移差函数;假定纵向翘曲位移沿横向分布为k次抛物线,并考虑剪滞和剪切双重效应的影响,通过能量变分法推导出了荷载横向变位时梁段单元的平衡控制微分方程组及其闭合解;提出了能对工程中常见的变截面连续箱梁剪滞效应进行分析的有限梁段法。该方法计算结果与有限元模型、已有模型试验结果的最大误差在5.95%~9.74%之间,两种工况下计算结果的叠加与有限元结果相对误差在0.07%~19.18%之间,均吻合良好,说明将基于有限梁段法的剪滞效应变分解和叠加原理用于求解复杂力状态下的剪滞效应是可行的。剪滞翘曲位移横向分布函数精度选择的研究结果表明:均布荷载分别作用于腹板顶部、顶板中心时,翘曲位移横向分布函数宜分别选用三次、二次抛物线。
[Abstract]:In order to study the effect of lateral load position change on shear lag effect of box girder, different shear lag longitudinal displacement difference functions are set for the top, bottom plate and cantilever plate of box girder, assuming that the longitudinal warping displacement is k times parabola along the transverse distribution. Considering the effects of shear lag and shear, the equilibrium control differential equations and their closed solutions of beam segment elements under transverse load displacement are derived by the energy variational method. This paper presents a finite beam segment method which can be used to analyze the shear lag effect of continuous box girder with variable cross section. The maximum error of the existing model test results is between 5.95% and 9.74%, and the relative error between the calculated results and the finite element results is between 0.07% and 19.18%, which is in good agreement with each other. It is shown that it is feasible to apply the variational decomposition of shear lag effect based on finite beam segment method and the principle of superposition to solve the shear lag effect under complex forces. The results of the study on the accuracy selection of the transverse distribution function of shear lag warpage displacement show that when the uniform load acts on the top of the web and the center of the roof, the transverse distribution function of the warpage displacement should be chosen three times and two times parabola respectively.
【作者单位】：铁道第三勘察设计院集团有限公司;中南大学土木工程学院;
【基金】：国家自然科学基金(51078356)
【分类号】：U448.213

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