金属阻尼器消能减震体系的等阻尼比设计方法

为合理有效地简化金属阻尼器消能减震结构体系的设计，提出了“等阻尼比”的设计原则，在设计性能水准的地震作用下使所有阻尼器自身的等效阻尼比相等，该原则在实际参数设计时可等价于更便于应用的“等延性系数”原则。该原则是一种概念优化设计原则，目的是使所有阻尼器都能充分发挥其阻尼耗能作用，从而以较小的代价来实现预定的减震控制效果。应用该原则可简化等效附加阻尼比的估算，并将金属阻尼器减震体系的刚度参数与阻尼参数进行解耦，使参数的确定过程更简便。基于“等阻尼比”原则，提出了金属阻尼器消能减震体系的实用设计方法，该方法采用以金属阻尼器延性系数和体系刚度特征参数为设计控制参数，以地震作用下层间位移角的性能需求为设计目标，以等效单自由度体系计算位移响应的求解模型。建立了体系等效阻尼比和等效周期的快速估算式，进而给出了两个控制参数的确定方法及阻尼器布置建议。通过对一个钢筋混凝土框架减震结构的设计和性能验算证实了所提方法的可行性与可靠性。

Constant damping ratio design method for damping controlled structures with metallic yielding dampers

In order to effectively simplify the design procedure of a damping controlled structure with metallic yielding dampers, a design principle termed ‘constant damping ratio’ is proposed. The ‘constant damping ratio’ principle means that all the installed dampers have a constant equivalent viscous damping ratio under seismic excitations, and this principle can be simplified into the ‘constant ductility coefficient’ principle for convenience. The ‘constant damping ratio’ principle can be considered as a conceptual optimization because it can make sure that every damper installed in the structure can be taken full advantages of, and thus satisfactory damping effect can be obtained at relatively small costs. Meanwhile, based on the ‘constant damping ratio’ principle, the evaluation formula of the equivalent additional damping ratio can be simplified and the stiffness parameter and damping parameter in damping ratio evaluation formula can be decoupled in appearance so that the parametric decision procedure can be more simple and convenient. A practical design method is proposed according to ‘constant damping ratio’ principle for structures with metallic yielding dampers. There are two key parameters in the proposed method, that is, damper’s ductility coefficient μ and system’s stiffness characteristic factor. The method is aimed to satisfy the seismic performance demand and an equivalent SDOF system of the structure is needed for fast response estimation. The formula to evaluate equivalent damping ratio and equivalent period are provided and the key parameters can be thus determined quickly. Besides, the proposals for the arrangement of dampers are also provided. Finally, a reinforced concrete frame structure with metallic yielding dampers is designed and the seismic performance is checked. The design example proves that the proposed method is of convenience and feasibility.