基于能量原理的板桁结合型加劲梁连续化分析方法

发布时间：2018-06-10 20:08

本文选题：桥梁工程 + 大跨径悬索桥　；参考：《中国公路学报》2014年06期

【摘要】：针对大跨径板桁结合型加劲梁悬索桥精细有限元模型单元数量多、计算效率低的特点,基于能量原理推导了板桁结合型加劲梁主桁架腹杆和下平联的连续化等效板厚计算公式,根据板桁结合型加劲梁的弯曲与扭转受力特点分别构造了相应的连续化等效截面,并采用悬臂梁模型验证等效截面的合理性,最后以主跨跨径1 480m的岳阳洞庭湖大桥为研究对象,将连续化分析方法与精细有限元法的位移与应力计算结果进行了比较。结果表明:采用2种方法计算得到的加劲梁位移的结果吻合较好,最大相对误差不超过4%;移动荷载作用时,采用连续化分析方法计算得到的上弦杆压应力受桥面板剪力滞效应的影响,导致其压应力的相对误差较下弦杆大,但上弦杆压应力的绝对差值不超过5.0MPa;横桥向静风荷载作用下,采用连续化分析方法计算得到的弦杆应力相对误差不超过5%;连续化分析方法的计算精度能满足要求,计算效率较精细有限元法大幅提高。
[Abstract]:In view of the large number of fine finite element model elements and low computational efficiency of long-span plate-truss stiffened girder suspension bridge, the continuous equivalent plate thickness calculation formula of the main truss web member and the bottom flat connection of the plate-truss combined stiffened beam is derived based on the energy principle. According to the bending and torsional stress characteristics of stiffened beam with plate and truss, the corresponding continuous equivalent section is constructed, and the rationality of equivalent section is verified by the cantilever beam model. Finally, taking the Yueyang Dongting Lake Bridge with a main span of 1480m as the research object, the results of displacement and stress calculation of the continuous analysis method and the fine finite element method are compared. The results show that the results of displacement of stiffened beam calculated by two methods are in good agreement with each other, and the maximum relative error is less than 4. The compression stress of the upper chord calculated by the continuous analysis method is affected by the shear lag effect of the bridge deck, resulting in the relative error of the compressive stress is larger than that of the lower chord, but the absolute difference of the compression stress of the upper chord is not more than 5.0 MPA, and the absolute difference of the compressive stress of the upper chord is less than 5.0 MPA under the static wind load. The relative error of chord stress calculated by continuous analysis method is not more than 5. The accuracy of continuous analysis method can meet the requirements and the computational efficiency is greatly improved compared with fine finite element method.
【作者单位】：长安大学公路学院;重庆大学土木工程学院;兰州大学土木工程与力学学院;长安大学建筑工程学院;
【基金】：交通运输部西部交通建设科技项目(2013 318 798 320) 湖南省交通科技项目(201219)
【分类号】：U448.25

【参考文献】