基于混合萤火虫-模拟退火算法的斜拉桥纵向振动控制与黏滞阻尼器优化设计

Longitudinal Vibration Control and Optimization Design of Viscous Dampers for Cable-stayed Bridges Based on Hybrid Firefly Simulated Annealing Algorithm

为研究多荷载组合作用下大跨斜拉桥纵向黏滞阻尼器的最优振动控制效果,首先,通过有限元计算分析了地震作用、风荷载和随机车流分别作用下纵向黏滞阻尼器对结构主要响应的振动控制作用。其次,结合标准萤火虫算法和模拟退火算法的优缺点,提出了混合萤火虫-模拟退火算法(HFSA),并选用4种测试函数进行了验证。最后,考虑3种荷载不同权重,选取合适的加权系数组合,采用响应面法拟合3种荷载的目标函数,分别对地震设防烈度和平均风速两个影响因素下的纵向黏滞阻尼器关键参数进行了优化,并给出了参考建议取值。结果表明:外荷载作用下纵向黏滞阻尼器可有效对结构振动产生控制效果,其中地震作用下的响应最大,随机车流次之,风荷载较小;随着黏滞阻尼器速度指数α的减小、阻尼系数C的增大,控制效率也逐渐增大,控制效率最大可达到45.15%;提出的HFSA算法具有收敛速度快、优化精度高的特点;速度指数α在[0.2,0.4]之间,阻尼系数C在[4000,5000]kN/(m/s)^α时控制效果达到最优;在地震多发、抗震烈度高的地区建议选取加权系数组合2,在沿海、山谷等风速较大区域建议选取加权系数组合4。

In order to optimize the vibration control effect of longitudinal viscous damper for long-span cable-stayed bridge under multi-load combination,first,the vibration control effect of longitudinal viscous damper on the main structural response under seismic action,wind load and random traffic flow is analysed by FE calculation.Second,combining the advantages and disadvantages of standard firefly algorithm and simulated annealing algorithm,a hybrid firefly simulated annealing algorithm(HFSA)is proposed and verified by 4 selected test functions.Finally,considering the weights of 3 loads and selecting an appropriate combination of weighted coefficients,the objective functions of the 3 loads are fitted by response surface method,the key parameters of the longitudinal viscous damper under the influencing factors of seismic fortification intensity and average wind speed are optimized,and the recommended values are given for reference.The result shows that(1)Longitudinal viscous damper can effectively control the structural vibration under external loads.Among them,the response under earthquake is the largest,followed by random traffic flow,and wind load is smaller.(2)With the decrease of velocity indexαand the increase of damping coefficient C of the viscous damper,the control efficiency increases gradually,and the maximum control efficiency can reach 45.15%.(3)The proposed HFSA algorithm has the characteristics of fast convergence and high optimization accuracy.(4)The control effect is optimal when the velocity indexαis between[0.2,0.4]and the damping coefficient C is between[4000,5000]kN/(m/s)α.(5)It is recommended to select weighted coefficient combination 2 in the areas with frequent earthquakes and high seismic intensity,and to select weighted coefficient combination 4 in the areas with high wind speed such as coastal areas and valleys.