有约束的最小能量法优化系杆拱桥成桥索力

为优化成桥索力,借鉴斜拉桥成桥索力的优化方法——有约束的最小能量法。以某系杆拱桥为工程背景,采用Midas/civil建立有限元模型,以各吊杆索力为自变量,求得主拱拱肋和主梁的拉压及弯曲应变能之和作为因变量,并限定节点位移、截面弯矩,以及吊杆索力。采用MATLAB建立数学模型求得最优成桥索力,并与刚性连续梁法、刚性吊杆法所得索力,以及成桥状态对比。有约束的最小能量法求得的索力使得主拱挠度平顺,拱脚处的弯矩更为合理。

Optimization Calculation of Reasonable Status of Completed Tied Arch Bridge by the Constrained Minimum Energy

The constrained minimum energy method,which was usually used to optimize the reasona-ble status of cable stayed bridge ,could be applied to optimize the cable tension of tied arch bridge. Based on a tied arch bridge,the finite element model was built by Midas/civil.The mathematical model built by Matlab determines the optimum cable tension of completed bridge,in which the cable tension is variable,the whole deformation energy of the arch rib and the beam is the objective func-tion,the displacement of the appointed node,the bending moment of the appointed section and the ca-ble tension is limited.It was compared to the results that were calculated by the rigid girder method and the rigid cable method.The constrained minimum energy method makes that the deformation of main arch is smooth and the bending moment of arch spring is low.