基于混合遗传算法的高速公路桥梁风屏障参数优化

为了优化高速公路桥梁风屏障参数,研究了风屏障参数对于车桥系统气动特性的影响.通过风洞试验考虑不同高度和透风率的风屏障,分别获取桥梁和车辆的气动力系数,进而得到桥梁在静风稳定性检验风速下的侧向位移和车辆在设计车速行驶下的失稳临界风速.采用多目标遗传算法(NSGA-Ⅱ),以桥梁侧向位移与车辆临界风速为优化目标,将风屏障高度和透风率作为变量,得到相应的Pareto最优解集.利用数据包络法(DEA)对Pareto解集中个体的相对效率值进行评估,最终得到最优风屏障参数.结果 表明:透风率为30％、高度为3.2 m的风屏障对于桥梁和车辆的综合抗风效果最佳.

Parameter Optimization of Wind Barrier forHighway Bridge Based on Hybrid Genetic Algorithm

The impacts of wind barrier parameters on the aerodynamic characteristics of the vehicle-bridge sys?tem are investigated to optimize the wind barrier parameters of the highway bridge. Based on wind tunnel tests con?sidering the wind barriers with different heights and ventilation rates, the aerodynamic coefficients for the bridge andthe vehicle are obtained, respectively. Afterward, the lateral displacement of the bridge under testing wind speed ofaerostatic stability and the critical wind speed of aerostatic instability for the vehicle running with the design speedare calculated, respectively. A multi-objective genetic algorithm (NSGA-II) is applied to obtain the related Pareto op?timal solution set. In the algorithm, the lateral displacement of the bridge and the critical wind speed for the vehicle are considered as optimal objectives. Meanwhile, the height and the ventilation rate of the wind barrier are regardedas the variables. Taking advantage of the Data Envelopment Analysis (DEA) to evaluate the relative efficiency of theindividual in the Pareto solution set, the optimal parameter of the wind barrier can be determined finally. The resultsshow that the wind barrier with the ventilation rate of 30% and the height of 3.2 m has the best performance in consid?eration of the wind-resistant effect for both the bridge and the vehicle.