曲线双工字钢组合梁桥横梁受力分析研究

为了研究主梁腹板纵桥向翘曲变形对横梁内力的影响,在现有横梁框架模型基础上,根据符拉索夫薄壁结构理论得到集中荷载作用下简支曲线双工字钢组合梁桥翘曲变形、结构扭转角等物理参数沿跨径的分布规律。利用主梁腹板与横梁的变形协调关系分析横梁的纵桥向变形,得到横梁内力组成以及截面正应力分布规律并进行有限元分析验证。结果表明:基于符拉索夫薄壁结构理论分析得到的横梁截面正应力分布规律与有限元计算得到的规律基本一致; 靠近加载点的横梁正应力以“竖向弯曲效应”为主导,靠近支座截面的横梁“腹板变形不一致效应”大于加载点截面附近横梁; 加载点截面两侧腹板翘曲变形方向相反,导致横梁的截面正应力分布规律相反; 横梁竖向弯曲变形产生的应力与主梁弯矩分布规律类似,纵桥向弯曲变形产生的应力与扭率分布规律类似。

Research on Internal Force of Crossbeam in Curved Steel-concrete Composite Twin I-girder Bridge

In order to study the influence of the longitudinal warpage deformation of the main beam web on the internal force of the crossbeam, on the basis of the existing crossbeam frame model, the distribution laws of physical parameters such as warpage deformation and structural torsion angle of a simply supported curved steel-concrete composite twin-I girder bridge under concentrated load were obtained through the Vlasov's thin-wall structure theory. The deformation coordination relationship between the main beam web and the crossbeam was used to analyze the longitudinal deformation of the crossbeam. The internal force composition of the crossbeam and the normal stress distribution law of the section were obtained and verified by the finite element analysis. The results show that the positive stress distribution law of the crossbeam based on Vlasov's thin-wall structure theory is basically consistent with the law obtained from finite element calculation. The crossbeam positive stresses near the loading point are dominated by the “vertical bending effect”, and the “web deformation inconsistency effect” of the crossbeam near the bearing section is greater than that of the crossbeam near the loading point section. The warpage deformations of the web on both sides of the loading point section are in opposite directions, which leads to the opposite distribution of the crossbeam positive stress. The distribution law of stress generated by the crossbeam vertical bending deformation is similar to that of the main beam bending moment, and distribution law of the stress generated by the longitudinal bending deformation is similar to that of the torsion rate.