薄壁箱梁剪力滞效应数值计算

运用有限元方法，采用板壳单元——Shell 63单元，对薄壁直线箱梁和薄壁曲线箱粱剪力滞效应分别进行了数值计算．将直线箱梁剪力滞效应的数值计算结果与变分法理论计算值及模型试验值进行了对比，三者吻合较好。验证了本研究数值方法的正确性．在有限元理论的基础上，进一步计算了曲线箱梁在静力荷载作用下的挠度、应力、应变及剪力滞系数值，分析了曲率半径等因素对曲线箱梁剪力滞效应的影响．计算结果表明，曲率半径对曲线箱梁的剪力滞效应影响较大．与直线箱梁相比，截面相同位置处的剪力滞系数随曲率半径的减小而增大，增幅远超过5％以上．因此在曲线箱梁的设计中应对曲率半径加以考虑．

Numerical calculation on shear lag effect of thin-walled box girder

The numerical calculation of the shear lag effect of the thin-walled straight box girder and the thin-walled curved box girder is carried out respectively by using the finite element method based on the board shell unit-Shell 63 unit. The computational results agree well with the predicted value of variational method and the experimental data, which validates the exactness of the numerical method. Then primary research is carried out on computing the amount of deflection, stress, strain and shear lag coefficient of the thin-walled curved box girder under static load and analyzing the influence of curvature radius on the shear lag effect of the thin-walled curved box girder. The computational results show that curvature radius have significant influence on the shear lag effect of the thin-walled curved box girder, the shear lag coefficient increases as the curvature radius decreasing on the same position compared with the thin-walled straight box girder, and the amplitude increases more than 5%. Therefore, the curvature radius should be considered in the design of thin-walled curved box girders.