阻尼耗散能量是基于能量性能抗震设计方法的重要指标,需要深入研究不同的地震动和结构特征参数下阻尼耗能的分配特征.以3种场地下的214条近断层地震记录为输入,以简化为理想弹塑性(EPP)、双线性(BL)和刚度退化(SD)滞回模型的单自由度体系的抗震结构在大量近场地震作用下的阻尼耗能分析为基础,从地震动特征和结构特性参数两种角度分别定量讨论了多种因素对结构阻尼耗能比值谱的影响规律.分析表明,场地土类型和断层距对阻尼耗能比的影响并不明显,持时和地震动峰值加速度在不同的周期和延性条件下对阻尼耗能分布比例有一定程度的影响,决定阻尼耗能分配比例的主要因素是结构阻尼、变形延性系数和结构自振周期.通过与计算结果的对比,指出了Akbas所建议计算方法存在的不足.研究成果对于探讨提高阻尼耗能的有效方法,发展基于能量原理的结构性能抗震设计方法具有参考价值.
Earthquake energy dissipated by structure damping is an important indicator for energy-based performance seismic design method, which requires in-depth study of the distribution characteristics of damping dissipated energy under different ground motion and structural parameters. With 214 near-fault earthquake records from 3 kinds of site soil as excitation, and through considering the ratio of damping dissipated energy to input energy, the influence of ground motion and structural characteristic parameters were investigated quantitatively by numerical analysis of seismic structures, simplified as SDOF system with elastic-perfectly plastic (EPP), bihnear (BL) and stiffness degradation (SD) hysteretic models respectively. It can be drawn that the influence of site soil and fault distance is not obvious, earthquake duration and peak ground acceleration plays certain role under some structural period and deformation ductility, and the major factors for damping energy distribution are structural damping, deformation ductility coefficient and self-vibration period of the structure. The defect of the proposed energy ratio model by Akbas was discussed with numerical results. The research result is valuable for the enhancement of damping dissipated energy and the application of energy-based seismic design method.