基于响应面法的系杆拱桥吊杆初内力优化

为精确优化系杆拱桥的吊杆内力,提出基于响应面法的系杆拱桥吊杆内力优化方法,优化过程包括试验设计、有限元分析、响应面函数拟合和内力优化。以一跨72m系杆拱桥为例,选取各个吊杆初始内力作为自变量,系梁、拱肋的关键截面弯矩以及系梁关键截面位移和结构应变能作为因变量;采用Box-Behnken试验设计方法进行样本点试验设计,采用显式响应面函数拟合结构静力响应值与吊杆内力间复杂的隐式关系。确定目标函数和多约束条件,采用优化软件对多约束条件下的吊杆内力进行优化分析,给出了成桥在多约束条件下的吊杆最优初内力。研究结果表明：该方法可以很好地对系杆拱桥吊杆初内力进行优化,为系杆拱桥的设计和施工控制提供指导。

Optimization of Initial Internal Forces of Hangers for Tied-arch Bridge Based on Response Surface Method

Based on response surface method,a method for optimizing the internal forces of hanger was presented.The process of method included test design,finite element analysis,response surface function fitting and internal force optimization.A tied-arch bridge was analyzed to illustrate the method.All initial internal forces of hanger were treated as independent variables,and some data were treated as dependent variables such as tie beam moment value of key section,arch rib moment value of key section of tie beam,displacement of key section,and structure strain energy.The method of Box-Behnken was used to design the sample,and the explicit response surface function fitting was used to express the complex implicit relationship between static structure response value and hanger forces.The objective function and constraints were determined,and the optimization software was used to optimize the initial internal forces of hangers under different constraints,and the optimal initial forces were obtained through this method.The results indicate that this method can optimize the initial internal forces of hangers,and can provide guidance for design and construction control.