基础隔震层附加黏滞阻尼器结构优化设计方法

Optimal design method for structures with viscous dampers in base isolation layer

摘要:

为合理有效地进行基础隔震结构隔震层黏滞阻尼器设计,提出一种根据隔震层位移和剪力设计侧重需求确定阻尼器参数的优化设计方法。针对隔震层设置黏滞阻尼器的基础隔震结构建立地震能量平衡方程,给出由地震结束时刻总输入能量预测隔震层最大位移与总剪力系数的简易方法,并利用动力时程分析验证预测法的准确性,结果表明阻尼器附加阻尼比越大则预测精度越好。分析了最优剪力设计下的隔震层响应降低效果。基于求解响应比组合函数极小值的设计原则,利用隔震层位移响应比与总剪力响应比的线性组合构建优化设计目标函数,并分析了4种典型目标下的隔震层响应特性,在此基础上给出隔震层附加黏滞阻尼器的优化设计流程。最后通过对 6 层钢框架基础隔震结构进行优化设计和时程分析验算,验证了方法的可行性与高效性。本文预测法可作为一种具有较好的准确性及安全性的响应验算方法；设计法优化了基础隔震结构隔震层位移与剪力响应,设计流程简单且适合手算,是一种高效的隔震层附加黏滞阻尼器优化设计方法。

Abstract:

In order to effectively design the viscous dampers in the isolation layer of base-isolated structures, an optimal design method was proposed to determine the damper parameters with the design emphasis of displacement and shear force of isolation layer. The seismic energy balance equation of base-isolated structures with viscous dampers was established. A simple method was given for predicting the maximum displacement and total shear coefficient of isolation layer using input energy at the end of earthquake. The accuracy of the prediction method was verified by dynamic time history analysis. Results show that the prediction accuracy increased with the increase in the additional damping ratio. The response reduction effect of the isolation layer under the optimal shear design was analyzed. Based on the design principle of solving the minimum value of the combination function of response ratios, an objective function for the optimal design was constructed by using the linear combination of total shear response ratio and displacement response ratio. The responses of the isolation layer under four typical design objectives were analyzed, and the optimal design process of the isolation layer with viscous dampers was given. Finally, a six-story steel frame base-isolated structure with viscous dampers was designed and its seismic performance was verified. The design example proved that the optimal design method is of feasibility and convenience. The prediction method can be used as a response checking method with good accuracy and safety. The viscous dampers design method which can optimize the displacement and shear response of isolation layer is efficient, and the design process is suitable for manual calculation.