稳定型悬索桥空间非线性三阶段综合优化方法

SPATIAL NONLINEAR INTEGRATED OPTIMAL METHOD FOR STABLE SUSPENSION BRIDGE IN THREE STAGES

针对稳定型悬索桥设计中的难点问题,建立其空间参数化有限元模型,提出先零阶再一阶的综合优化方法,考虑稳定型悬索桥的形成过程和几何非线性效应,分三个阶段对稳定型悬索桥进行逐步深入的优化。在优化的过程中,以跨中挠度为目标函数,以各种几何和应力边界为约束,以稳定型悬索桥设计中的关键因素,诸如缆索的初始张拉应变、吊杆的长度和桥塔的高度等为设计变量。另一方面,对零阶方法、一阶方法和综合优化方法的优化效果进行了比较研究。通过对稳定型悬索桥的全面优化,从而使稳定型悬索桥的受力和变形达到均匀而合理的状态。

A stable suspension bridge is parametrically modeled in a three-dimensional space for its design difficulties and an integrated optimal method for the design is proposed, which combines the zero-order method and the first-order method. Considering the construction and nonlinearity of the bridge, the whole optimal process is divided into three stages in order to optimize the bridge step by step, with the mid-span deflection as the object function and the geometric as well as stress boundary conditions as the constrains. In the course of optimization some critical factors, such as the initial tension strains of the cables, the lengths of the suspenders and the height of the towers, are considered as design variables. On the other hand, the zero-order method, the first-order method and the presented integrated optimal method are compared, about the optimization effect to the bridge. After the full optimization, the stable suspension bridge arrives at a rational state pertinent to the force and deformations.