摘要
为克服大跨度桥梁主梁断面气动选型过程中几何参数多、潜在组合多、试验工作量大的难题,提出基于“均匀试验设计+Kriging代理模型”优化策略的桥梁断面气动外形优化方法。以某大跨桥梁中央开槽箱梁颤振性能优化为例,采用该方法进行气动外形优化。基于计算流体动力学(CFD)数值模拟,首先通过“均匀试验设计”合理选取CFD分析工况,再利用“Kriging代理模型”以尽可能少的工况建立主梁几何参数-颤振临界风速关系模型,基于该模型分析不同几何参数对桥梁颤振性能影响规律,获取最优主梁断面。结果表明:“均匀试验设计+Kriging代理模型”优化策略能够在保证模型精度的前提下显著减少计算工况,工作量仅为遍历性试验的0.68%;CFD数值模拟、试验设计与代理模型策略的结合可以快速评估不同几何参数对抗风性能的影响规律,在背景桥梁主梁高度和行车道宽度下,中央开槽箱梁的颤振最优参数为槽宽比D/B=0.12、风嘴角度α=44°、下斜腹板倾角β=11°。
In this paper,a method based on Kriging Surrogate Modelling is proposed,which can be used to optimize the aerodynamic shape of girder cross-sections of long-span bridges.Compared with the conventional aerodynamic shape selection methods,the proposed method reduces the amount of the required geometric parameters,parameter combinations and testing work.The split box girder of a long-span bridge,on which the proposed method has been employed for aerodynamic shape optimization,is used as a study case.Based on the Computational Fluid Dynamic(CFD)modeling,the load cases for analysis is first selected via uniform experimental design,then a model reflecting the relationship between main girder geometric parameters and critical flutter speed is established using the Kriging Surrogate Model,with possibly smallest number of load cases.In this model,the influence of varying geometric parameters on the flutter performance of bridge is analyzed to obtain the optimal pattern of girder cross-section.The results show that using the uniform experimental design and Kriging Surrogate Model in combination to optimize the girder cross-section can significantly reduce the load cases in calculation,without compromising the modeling accuracy,the work volume is 0.68%of the full-factor experiment.The combined utilization of CFD modeling,experimental design and surrogate model can rapidly assess the influence of varying geometric parameters on the wind resistance of the structure.With the depth and vehicle lane width as the parameters,the optimal gap width-to-girder width ratio,wind fairing angleαand inclination of lower oblique webβare 0.12,44°and 11°,respectively.
作者
赵林
方根深
展艳艳
陈逸群
葛耀君
ZHAO Lin;FANG Gen-shen;ZHAN Yan-yan;CHEN Yi-qun;GE Yao-jun(State Key Laboratory of Disaster Reduction in Civil Engineering,Tongji University,Shanghai 200092,China;Key Laboratory of Transport Industry of Bridge Wind Resistance Technologies,Tongji University,Shanghai 200092,China;Shanghai Municipal Transportation Design Institute Co.,Ltd.,Shanghai 200025,China)
出处
《桥梁建设》
EI
CSCD
北大核心
2022年第6期25-32,共8页
Bridge Construction
基金
国家自然科学基金项目(52108469,51978527)
上海市浦江人才计划(20PJ1413600)。
