曲线连续钢箱梁的设计及空间有限元分析

DESIGN AND FINITE ELE MENT ANALYSIS OF CURVED CONTINUOUS STEEL BOX GIRDER

以苏州中环高架为工程实例,通过ANSYS软件建立空间有限元模型,对曲线钢箱梁的力学性能进行了详细分析。最后,采用MIDAS建立单梁模型与ANSYS空间实体模型进行比较。结果表明:ANSYS结果和MIDAS结果基本吻合;单梁模型在偏载作用下,无法体现横桥向应力分布状态,实体模型理论上更接近实际应力状态;钢箱梁顶底板作为主梁上翼板参与整体受力时,有效分布宽度具有支点处比跨中小的特点,支点处应力峰值更大,而跨中应力分布相对均匀;支点处主要受力构件均需加强,以便削减应力峰值,扩大有效分布宽度范围,使得各主要构件受力均衡;应力状态和位移等结果表明,钢吊箱结构整体构造合理,应力和位移均满足规范要求,可为类似工程提供参考价值。

Taking Suzhou Zhonghuan viaduct as an example, this paper analyzed the mechanical property of curved steel box girder by establishing 3D finite element model in ANSYS. Afterwards, single beam model （MIDAS） and 3D entity model （ANSYS） have both been set for comParison. It can be seen that the results of model of ANSYS almost matches the model of MIDAS. Under Eccentric load, single beam model could not show the stress distribution in transverse direction. However, entity model in ANSYS models the whole actual bridge, which is more realistic than single beam model. When the upper and lower plates of steel box girder participate the overall force system and act as flange slab, the effective distribution width near bridge pillar is smaller than mid-span, the stress peak is higher in pillar, while the stress distribution is more even in mid-span. For the sake of even distribution of stress, all the main force members near pillar need to be strengthened to reduce the peak stress and increase the effective stress width, the results of stress condition and displacement show that steel hanging box structure is safe because the stress and displacement satisfy the Chinese standard. It could make contribution for the future construction of this kind of structure.