基础隔震结构的系统参数优化设计

Parameter Optimization of Base-Isolated Structure

目的为了改善基础隔震结构的减震效果,实现基础隔震结构设计的可靠性和有效性,得到基础隔震结构的系统优化参数.方法建立了基础隔震结构的动力分析模型,推导出其运动微分方程;对标准遗传算法经常出现未成熟收敛、振荡、随机性太大和迭代过程缓慢等缺点进行改善,提出了改进混合遗传算法;建立基础隔震结构系统参数优化设计模型,使用改进混合遗传算法对7层LRB隔震结构的系统参数进行优化设计.结果优化后,LRB隔震结构的相对加速度峰值、相对速度峰值、相对位移峰值和层间剪力峰值分别比优化前有不同程度的降低.结论工程实例计算结果表明改进混合遗传算法对基础隔震结构的系统参数优化效果比较理想,基础隔震结构的各项地震反应均得到了更好地控制.

In order to improve the effect of shock absorption of base- isolated structure with LRB, optimal parameters are found. The dynamic analysis model for base - isolated structure with LRB is set up, and kinetic differential function is presented accordingly. Considering that the standard genetic algorithm （SGA） has such frequent shortcomings as premature convergence, oscillation and over - randomization in iterative process, a new genetic operator named transgenic operator has been developed for the purpose of improving SGA. Moreover, a fibonacci algorithm （FA） for structural optimization with discrete variables is proposed, and some problems are solved by means of FA combined with IGA. Thus, improved hybrid genetic algorithm （IHGA） is proposed. The optimal model for base - isolated structure with LRB is set up. The parameters of base-isolated structure with LRB are optimized with IHGA. The relative acceleration, velocity, displacement and interstory shear of structure with LRB are reduced greatly by optimization. It shows that IHGA is an effective method for parameter optimization of base - isolated structure. The various earthquake responses of base - isolated structure with LRB get better control after it is optimized with IHGA.