大跨独塔斜拉桥纵隔板的极限承载力

为保证主跨383 m的广州珠江黄埔大桥北汊桥主梁吊装施工期间钢箱梁桁架式纵隔板的稳定性,对集中荷载作用下纵隔板的极限承载力进行了非线性有限元数值模拟和模型试验.采用通用有限元软件ANSYS建立梁段的空间数值模型,得到了设计荷载作用下纵隔板的应力分布及施工阶段结构的弹性屈曲系数;考虑材料及几何非线性和初始缺陷,得到了该纵隔板的极限承载力.采用1∶2.5缩尺模型对纵隔板进行了静载试验,得到了设计荷载作用下纵隔板的应力和变形;通过极限承载力试验,得到了设计荷载作用下纵隔板的非线性屈曲系数.研究结果表明:该斜拉桥钢箱梁纵隔板设计合理,其稳定性满足设计要求;考虑初始缺陷的非线性有限元分析可用于研究钢箱梁纵隔板的局部稳定性.

Limit Bearing Capacity of Longitudinal Clapboard of Long-Span Single Pylon Cable-Stayed Bridge

In order to investigate the limit bearing capacity of longitudinal clapboard,nonlinear buckling analysis and model test on the longitudinal clapboard used in streamlined steel-box girder of Pearl River Huangpu bridge in Guangzhou were performed.Based on the ANSYS software,a refined finite element model for one section of the steel-box girder was founded.Stress distribution and elastic buckling coefficient of the longitudinal clapboard under a designed load were obtained by FEM(finite element method) analysis.By considering initial disfigurement,geometrical and material non-linearities,limit bearing capacity of the longitudinal clapboard was get.A static test on a specimen for a part of the steel-box girder with a scale of 1 to 2.5 was carried out to obtain stress and deformation of the longitudinal clapboard under the designed load.Nonlinear buckling coefficient of the longitudinal clapboard under the designed load was achieved through a test on the ultimate bearing capability of the specimen.The research results show that the stability of the longitudinal clapboard used in the Pearl River Huangpu bridge in the whole construction meets the need of design.Nonlinear FEM considering initial disfigurement can be used to investigate the local stability of the longitudinal clapboard of steel-box girder.