为研究斜拉桥其最优成桥索力对主梁内力、线形的影响,以本溪某混合梁斜拉桥为工程背景.在既有索力优化理论的基础上,采用了基于复合约束的最小能量法,以塔梁的拉压应变能和弯曲应变能建立目标函数,运用显示梯度的数学表达式进行求解.研...为研究斜拉桥其最优成桥索力对主梁内力、线形的影响,以本溪某混合梁斜拉桥为工程背景.在既有索力优化理论的基础上,采用了基于复合约束的最小能量法,以塔梁的拉压应变能和弯曲应变能建立目标函数,运用显示梯度的数学表达式进行求解.研究结果表明:钢梁侧最大负弯矩为83 292.49 k N·m,混凝土侧最大负弯矩为18 934.7 k N·m,主梁最大下挠为40.1 mm,出现在钢梁侧且距离主墩0.75 L处,优化后索力更加均匀合理,计算结果可以满足工程要求,在同类桥型中有良好的借鉴意义和参考价值.展开更多
A systematic and generic procedure for the determination of the reasonable finished state of self-anchored suspension bridges is proposed, the realization of which is mainly through adjustment of the hanger tensions. ...A systematic and generic procedure for the determination of the reasonable finished state of self-anchored suspension bridges is proposed, the realization of which is mainly through adjustment of the hanger tensions. The initial hanger tensions are first obtained through an iterative analysis by combining the girder-tower-only finite element(FE) model with the analytical program for shape finding of the spatial cable system. These initial hanger tensions, together with the corresponding cable coordinates and internal forces, are then included into the FE model of the total bridge system, the nonlinear analysis of which involves the optimization technique. Calculations are repeated until the optimization algorithm converges to the most optimal hanger tensions(i.e. the desired reasonable finished bridge state). The "temperature rigid arm" is introduced to offset the unavoidable initial deformations of the girder and tower, which are due to the huge axial forces originated from the main cable. Moreover, by changing the stiffness coefficient K in the girder-tower-only FE model, the stiffness proportion of the main girder, the tower or the cable subsystem in the whole structural system could be adjusted according to the design intentions. The effectiveness of the proposed method is examined and demonstrated by one simple tutorial example and one self-anchored suspension bridge.展开更多
文摘为研究斜拉桥其最优成桥索力对主梁内力、线形的影响,以本溪某混合梁斜拉桥为工程背景.在既有索力优化理论的基础上,采用了基于复合约束的最小能量法,以塔梁的拉压应变能和弯曲应变能建立目标函数,运用显示梯度的数学表达式进行求解.研究结果表明:钢梁侧最大负弯矩为83 292.49 k N·m,混凝土侧最大负弯矩为18 934.7 k N·m,主梁最大下挠为40.1 mm,出现在钢梁侧且距离主墩0.75 L处,优化后索力更加均匀合理,计算结果可以满足工程要求,在同类桥型中有良好的借鉴意义和参考价值.
基金Project(20133204120015) supported by Specialized Research Fund for the Doctoral Program of Higher Education of ChinaProject(12KJB560003) supported by the Natural Science Foundation of the Higher Education Institution of Jiangsu Province,China
文摘A systematic and generic procedure for the determination of the reasonable finished state of self-anchored suspension bridges is proposed, the realization of which is mainly through adjustment of the hanger tensions. The initial hanger tensions are first obtained through an iterative analysis by combining the girder-tower-only finite element(FE) model with the analytical program for shape finding of the spatial cable system. These initial hanger tensions, together with the corresponding cable coordinates and internal forces, are then included into the FE model of the total bridge system, the nonlinear analysis of which involves the optimization technique. Calculations are repeated until the optimization algorithm converges to the most optimal hanger tensions(i.e. the desired reasonable finished bridge state). The "temperature rigid arm" is introduced to offset the unavoidable initial deformations of the girder and tower, which are due to the huge axial forces originated from the main cable. Moreover, by changing the stiffness coefficient K in the girder-tower-only FE model, the stiffness proportion of the main girder, the tower or the cable subsystem in the whole structural system could be adjusted according to the design intentions. The effectiveness of the proposed method is examined and demonstrated by one simple tutorial example and one self-anchored suspension bridge.
