多高层隔震结构等效简化模型动力响应分析

Dynamic Response Analysis of Base-isolated High-rise Structures Using Equivalent Simplified Model

结合现有多高层隔震结构等效模型的研究基础,提出了多高层隔震结构等效模型的动力响应分析方法,使结构响应解析解具备明确的物理与工程意义。针对多层隔震结构等效简化后的两自由度模型,其运动方程的求解若采用实际工程中应用广泛的强振型解耦法将产生较大误差,采用Kelly法解耦求解可使求解结果精度大大提高。针对高层隔震结构等效简化后的三自由度模型,先采用强振型解耦法解耦,分析强振型解耦法求解的误差,对结果进行修正,即采用提升强振型解耦精度的方法求解同样可使求解精度大大提高。同时,用标准2阶振子的位移和速度表示非经典阻尼隔震结构的位移响应,使得现有基于经典结构的抗震设计方法可推广应用于具有非经典阻尼特性的隔震结构。结合两个算例,分别将多层和高层原结构简化为两自由度和三自由度模型,通过对原结构和等效简化模型对比求解验证了等效简化模型的有效性,且所提的针对非经典阻尼隔震结构的近似解耦求解方法是简单有效的,从而使得对于隔震结构的动力响应分析更加完备。

Based on the research foundation of the existing equivalent model of multiple high-rise isolated structures,a dynamic response analysis method for the equivalent model of multiple high-rise isolated structures was proposed,which makes the structural response analytical solution have clear physical and engineering significance.For a simplified structure with two degree of freedom equivalent multi-layer isolation system,since the solution of the equation of motion of the multi-layer isolation structure using the strong vibration decoupling method that is widely used in practical engineering will produce large errors,the Kelly decoupling solution can greatly improve the accuracy of the solution.And for a three degree of freedom equivalent model of isolated high-rise structure,decoupling using strong decoupling method was used to analyze the error of the strong vibration decoupling method,and the results were corrected,which indicated that,the method of lifting the strong decoupling accuracy can also greatly improve the accuracy of the solution.Also,isolated structure with non-classical damping was analyzed for dynamic displacement response with standard second order oscillator to show that the existing seismic design method based on classical structure can be applied to isolated structures with non-classical damping characteristics.The method was demonstrated using example,the original multi-layer structure and the high-level structure were simplified into two degree of freedom and three degree of freedom models,respectively.The validity of the equivalent simplified model was verified by comparing the original structure with the equivalent simplified model.At the same time,the approximate decoupling solution method for non-classical damping isolation structures is simple and effective.With this method the dynamic response analysis of isolated structures becomes more complete.