采用改进多目标粒子群算法的斜拉桥阻尼器参数优化

Parameter optimization of viscous damper for cable⁃stayed bridge using improved multi⁃objective particle swarm algorithm

为克服大跨度斜拉桥黏滞阻尼器优化设计效率低、多个相互制约的减震控制目标的问题难以权衡,基于遗传算法的“变异”方法,提出了改进多目标粒子群算法来进行阻尼器参数优化设计。建立大跨度斜拉桥的有限元模型,开展了全桥地震响应分析,根据抗震需求在桥梁纵向设置黏滞阻尼器;分别建立了塔底弯矩、阻尼力和梁端位移的减震响应与阻尼器参数之间的响应面数学模型;以减震响应面模型为研究对象,通过该算法进行阻尼器参数全局自动寻优分析,确定了阻尼器的最优参数,并与采用参数敏感性分析方法确定的一组阻尼参数进行对比分析。研究结果表明:该优化方法具有计算精度好、优化效率高和更好地权衡多个相互制约的减震控制目标的优点;通过优化算法获得的阻尼器参数组合相比采用参数敏感性分析方法获得的阻尼参数组合的减震响应,塔底弯矩增大1.73%,阻尼力减小5.97%,梁端位移减小1.66%;在无需多次有限元试算的基础上确定了更高精度的阻尼器优化参数组合,在提高减震效果的同时大大提升了计算效率。

Traditional designs of viscous dampers for large-span cable-stayed bridges often suffer from low efficiency and challenges in balancing multiple,mutually constrained damping control objectives.To address these issues,this paper proposes an improved multi-objective particle swarm algorithm for optimal damper parameters design,based on the"variational"method of genetic algo-rithms.A finite element model of a large span cable-stayed bridge was established,and a seismic response analysis of the entire bridge was conducted.Viscous dampers were installed in the longitudinal direction of the bridge according to the seismic demand.Response surface mathematical models were established to represent the relationships between the seismic responses of the tower bottom bending moment,damping force,beam end displacement,and the damper parameters.Using the seismic response surface model,a global automatic optimization search analysis of the damper parameters was performed using the proposed algorithm,re-sulting in the determination of the optimal damper parameters.Additionally,a set of damping parameter combinations were deter-mined for comparative analysis using the traditional parameter sensitivity analysis method.The results show that the optimization method offers good computational accuracy,high optimization efficiency,and a better trade-off among multiple,mutually con-strained seismic control objectives.The combination of damper parameters obtained by the optimization algorithm,compared to the damping response of the combination of damping parameters obtained by the conventional method,increases the bottom bend-ing moment of the tower by 1.73%,reduces the damping force by 5.97%,and reduces the displacement of the beam end by 1.66%.The optimized parameter combinations of dampers with higher accuracy are determined without the need for multiple finite element trial calculations,resulting in improved damping effect and significant time savings.