单室箱梁考虑剪切与剪滞双重效应的挠曲函数

Flexural Function of Single Chamber Box Girder with Doule Effects of Shear and Shear Lag

基于单室箱梁翼缘板选取最大剪切位移差函数为广义剪力滞位移函数,通过假定箱梁竖向变形由腹板剪切变形与翼板剪滞效应引起的位移,利用变形协调条件和能量变分法最小势能原理推导了特定边界和荷载条件下考虑剪切变形的单室箱梁的挠曲位移表达式。利用推导的挠曲微分方程计算了单室简支箱梁承受均布荷载作用下的挠度,对靠近梁端部采用挠度修正系数线性内插求解竖向变形,建立单室简支箱有限元分析模型;对比解析解和数值解。结果表明:剪切变形对简支单室箱梁承受均布荷载作用的挠度具有一定的影响;利用推导的公式能够快速、有效地计算简支单室箱梁承受均布荷载下剪切与剪滞双重效应的挠度;跨中挠度与数值解差6%,吻合良好。

Based on the selection of the maximum shear displacement difference function for the single-chamber box girder flange plate as the generalized shear lag displacement function,by assuming the vertical deformation by a web shear deformation and shear lag effect caused wing,the deflection displacement function under the double effect of shear deformation and shear lag of a single chamber box girder under specific boundary conditions and loads were derived by using the deformation coordination condition and the minimum potential energy principle of energy variation method.The deflection of single-story simple-supported box girder subjected to uniform load was calculated by using the deflection differential equation derived.The vertical deformation was solved by the linear interpolation of deflection correction coefficient near the end of the beam.Simple box girders single compartment model of finite element analysis was established and compared in this analytical and numerical solutions.The results show that the shear deformation has a certain influence on the deflection of simply supported single-chamber box girder subjected to uniform load.The formulas derived can be used to quickly and effectively calculate the deflection of double effect of simply supported single-chamber box girder subjected to uniform shear load and the results are in good agreement with the fem results.The deflection of the box girder span differs from the numerical solution by 6%.