Critical response of elastic-plastic SDOF systems with nonlinear viscous damping under simulated earthquake ground motions
Critical response of elastic-plastic SDOF systems with nonlinear viscous damping under simulated earthquake ground motions
复制标题
模拟地震地面运动下非线性粘滞阻尼弹塑性单自由度系统的临界响应
DOI：
10.1016/j.heliyon.2019.e01221
复制
发表时间：
2019
期刊：
影响因子：
4
通讯作者：
I. Takewaki
中科院分区：
文献类型：
--
作者：
G. Tamura;K. Kojima;I. Takewaki
以等时距多脉冲作为长时程地震动的代表。本文推导了具有非线性粘滞阻尼的单自由度（SDOF）模型在使响应最大化的“临界多冲量”作用下的弹塑性响应的解析表达式。在这种多脉冲作用下只出现自由振动的事实，使能量法在推导具有非线性粘性阻尼的复杂弹塑性响应的解析表达式中的巧妙应用成为可能。变形的非线性粘性阻尼特性近似于二次或椭圆函数。脉冲的临界时间被发现对应于零摩擦力时间或最大速度时间取决于输入水平。结果表明，在某些情况下，粘滞阻尼的非线性对结构的地震反应有显著的影响。通过与以调谐正弦波为代表的长时程地震动时程反应分析结果的比较，验证了该理论的可靠性和准确性。
Multi impulse with constant time interval is used as a representative of a long-duration earthquake ground motion. An analytical expression is derived for the elastic-plastic response of a single-degree-of-freedom (SDOF) model with nonlinear viscous damping subjected to the "critical multi impulse" which maximizes the response. The fact that only free vibration appears under such multi impulse enables the smart application of an energy approach in deriving the analytical expression for a complicated elastic-plastic response with nonlinear viscous damping. The nonlinear viscous damping characteristic for deformation is approximated in terms of a quadratic or elliptical function. The critical timing of the impulses is found to correspond to the zero restoring-force timing or the maximum velocity timing depending on the input level. It is shown that the nonlinearity in viscous damping causes a remarkable influence on the earthquake response in some cases. The reliability and accuracy of the proposed theory are investigated through the comparison with the results by the time-history response analysis to the tuned sine wave as a representative of the long-duration earthquake ground motion.