ABSTRACT

Until recently, the viscous damping ratio pervasively assumed has been $\zeta =5\mathrm{\%}$. However, the dynamic identification of the experimental response recorded in recent large-scale shake-table tests shows that lower levels of viscous damping are more appropriate when material nonlinearities are explicitly accounted for. This paper investigates a hybrid constant-ductility inelastic displacement ratio, $C_{\mu 2}$, which identifies the inelastic demand for a viscous damping ratio $\zeta =2\mathrm{\%}$ when the elastic demand for $\zeta =5\mathrm{\%}$ is known. A comprehensive statistical analysis is developed, and analytical estimates are provided, for inelastic single-degree-of-freedom systems with a wide variation of the constitutive parameters and a large earthquake database.

摘要

直到最近，普遍假设的粘性阻尼比$\zeta =5\mathrm{\%}$. 然而，在最近的大规模振动台试验中记录的实验响应的动态识别表明，当明确考虑材料非线性时，较低水平的粘性阻尼更合适。本文研究了混合恒延性非弹性位移比，$C_{\mu 2}$，它确定了对粘性阻尼比的无弹性需求$\zeta =2\mathrm{\%}$当需求弹性$\zeta =5\mathrm{\%}$是已知的。对于具有广泛变化的本构参数和大型地震数据库的非弹性单自由度系统，开发了全面的统计分析，并提供了分析估计。