Capacity Requreiment of Steel Moment Frames in Compliance with Seismic Demand

本研究取得的主要成果如下：1.在基于能量的抗震设计中，致损地震输入能量被定义为弹性应变能和塑性耗散能之和的最大反应。输入能量可以通过与框架的视自振周期相对应的拟速度反应谱来预测，视自振周期是根据整个振动过程中每半周塑性耗散能的平均值来确定的.最大半周能量输入比定义为半周振动过程中弹性应变能和塑性耗散能之和的最大增量与致损地震输入能量的比值。最大半周能量输入比进行了广泛的数值响应分析评估。提出了一种基于输入能量和吸收能量平衡的双线性体系最大地震反应和残余变形的预测方法， ...更多信息 振动的半周期。提出了一种等效单自由度体系，可以模拟多层框架的地震反应。本文提出了一种考虑各层水平动力相互关系的地震作用下倒塌机理的预测方法。基于预测的倒塌机理，确定了等效单自由度体系的荷载-变形关系.提出了强柱弱梁钢框架中梁延性需求的抗震设计方法。控制钢框架地震反应的关键参数的特点，并纳入等效单自由度表示。最大和累积塑性旋转诱导到梁端导出的显式形式作为这些参数的函数，并证明通过与数值结果比较估计旋转的准确性。少

The results obtained from this project are summarized as follows :1. Damage-causing earthquake input energy used in energy-based seismic design is defined as the maximum response of the sum of elastic strain energy and plastic dissipated energy. The input energy can be predicted by using a pseudo-velocity response spectrum corresponding to the apparent natural period of a frame, which is determined based on the mean of the plastic dissipated energy per half-cycle in the whole vibration.2. Maximum half-cycle energy input ratio is defined as the ratio of the maximum increment of the sum of elastic strain energy and plastic dissipated energy during a half-cycle of vibration to the damage-causing earthquake input energy. The maximum half-cycle energy input ratio is evaluated by extensive numerical response analysis. A method is proposed to predict the maximum seismic response and residual deformation of bilinear systems based on the balance between input energy and absorbed energy during a … More half-cycle of vibration.3. An equivalent single-degree-of-freedom system is proposed that can simulate the seismic response of a multistory frame. A method for predicting the collapse mechanism under earthquake excitations is devised, taking into consideration the correlation between dynamic horizontal forces acting on each story. In addition, load-deformation relationships of equivalent single-degree-of-freedom systems are determined based on the predicted collapse mechanism.4. A seismic design procedure is proposed to estimate the ductility demanded of beams in strong-column/weak-beam steel frames. Critical parameters that control the earthquake response of steel frames are characterized and incorporated into the equivalent single-degree-of-freedom representation. Maximum and cumulative plastic rotations induced into beam-ends are derived in explicit forms as functions of these parameters, and the accuracy of the estimated rotations is demonstrated through comparison with numerical results. Less