Dissipated-Energy Distribution Characteristics of Steel Moment Frames Incorporated with Hysteretic Dampers

本研究旨在建立装设滞回阻尼器之钢框架结构之抗震设计。为此，本论文主要研究了以下三个方面的问题：（1）低屈服钢阻尼器滞回性能的建模;（2）框架-阻尼器组合的动力试验;（3）钢框架-阻尼器组合的耗能和最大层间位移的预测。（1）建立了考虑低屈服钢滞回阻尼器明显应变硬化特性的数学模型。一个系统的程序，以确定包括在这个模型中的相关变量也提出了建议。（2）动载试验表明，在与加载速率有关的各种效应中，阻力（强度）的增加最为显著。（3）大量的数值分析得出以下结论。(a)控制耗散能量和最大层间位移沿着层分布的最显著参数是主框架的强度，只要主框架仅表现为弹性，则分布保持相对均匀。（B）当主框架响应超过其弹性极限时，层间位移倾向于集中在经历第一次屈服偏移的层上。（c）（B）中的观测结果表明，随着地震动幅值的增加，耗散能量和层间位移沿着的均匀性受到损害。

This study is toward the establishment of seismic design of steel moment frames incorporated with hysteretic dampers. To this end, the following three subjects were examined : (1)modeling of hysteretic behavior of dampers made of low-yield steel; (2) dynamic test applied to frame subassemblies combined with hysteretic dampers; and (3)prediction of dissipated energy and maximum story drift of steel moment frames with those dampers.Major findings obtained from this study are summarized as follows : (1)A mathematical model in which conspicuous strain hardening characteristic of the hysteretic dampers made of low-yield steel is explicitly allowed for was developed. A systematic procedure to determine the associated variables included in this model was also proposed. (2)Dynamic loading test indicated that among various effects associated with loading rate the increase in the resistance (strength) is most notable. (3)Extensive numerical analyses lead the following observations. (a) The most notable parameter that controls the distribution of dissipated energy and maximum story drift along the stories is the strength of the main frame, and the distribution remains relatively uniform as long as the main frame behaves only elastically. (b)When the main frame responds beyond its elastic limit the story drift tends to be concentrated at the story that experiences the first yield excursion. (c)The observation in (b)suggests that the uniformity of the dissipated energy and story drift along the stories is impaired with the increase of ground motion amplitudes.