摘要
根据混合梁斜拉桥的结构特点,考虑混凝土主梁和钢主梁结合处弯矩的限值,利用有限元方法建立混合梁斜拉桥成桥索力的优化模型.以塔梁的弯曲和拉压应变能之和为目标函数,以斜拉索的初张力为设计变量,成桥索力和主梁钢混结合处的弯矩为约束条件,结合ANSYS优化模块中的零阶和一阶方法进行求解,确定合理成桥状态下的索力.在优化过程中,改变结合处弯矩的限制范围,分析成桥下的内力和位移随限制范围变化的规律.通过一座单塔斜拉桥算例计算表明:将弯矩限值控制在0.3～0.5倍的主梁最小和最大弯矩范围内,得到的成桥状态最合理.索力从塔至边墩呈均匀增长趋势,主梁弯矩图变化平顺,结合处弯矩较小.
According to the characteristics of cable stayed bridges with mixed stiffening girders, the optimization model of cable tensions under the completed stage is built considering the constraint condition of moment limit at junction section by finite element method. Using the sum of the bending and tension-compression strain energy within tower and stiffening girder as objective function, the initial cable tensions as design variables, and the cable tensions under completed stage and the moment at the junction section of steel and concrete stiffening girders as constraint conditions, the optimization model was solved. The reasonable cable tensions under completed stage were obtained by zero-order and first-order methods of ANSYS optimization block. During the optimization process, the internal forces and displacements of bridge structures under completed stage were investigated by changing the moment limit at junction section. An actual cable stayed bridge with single tower and asymmetrical cable configuration was employed to illustrate the optimization model. The calculating result shows that the most reasonable completed state can be obtained by assigning the moment limit at junction section within the range of 0.3-0.5 times of minimum and maximum moment through the stiffening girder. The optimized state was characterized by the gradually increased cable tensions from the tower through the side supports, smooth moment distribution within the stiffening girder, and the smaller moment at junction section.
出处
《华中科技大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2010年第8期111-114,共4页
Journal of Huazhong University of Science and Technology(Natural Science Edition)
基金
湖北省自然科学基金资助项目(2004ABA041)
关键词
混合梁斜拉桥
弯矩
约束条件
零阶方法
一阶方法
合理成桥索力
cable-stayed bridges
girders
junction section moment
constraint conditions
zero-order method
first-order method
reasonable completed stage cable tensions
