【摘要】 根据基于美国NGA数据库统计分析得到的地震动频率成分随时间的变化规律,人工拟合强度和频率非平稳特性程度不同的3组地震加速度时程作为输入,利用多子台振动台台阵系统对国家体育馆双向张弦梁结构屋盖模型(平面尺寸11.4m×14.4m)进行单向和多向地震输入下的动力试验,用于研究地震动非平稳特性对结构响应的影响。试验结果表明,结构响应随着地震动稳态持续时间的加长有增大的趋势,并且地震输入能量的集中,将可导致结构响应增大;地震动频率非平稳特性对结构响应的影响和频率随时间的变化有直接关系,后段周期明显长于前段周期的地震输入,对结构响应的增大效应比较明显。此外,地震动强度和频率非平稳特性对结构响应的影响规律对于不同的约束条件基本是一致的。更多还原

【Abstract】 In order to investigate the influence of non-stationary characteristics of ground motion on structural response,vibration table model test of the national gymnasium bi-directional beam string structure(plane size is 11.4 m×14.4 m) is performed under the one-directional and multiple-directional ground motion inputs by using a multiple vibration table array system,and the 3 groups of acceleration time histories are fitted with various non-stationary characteristics of intensity and frequency.The time-frequency characteristics of the ground motions are obtained through analyzing the acceleration records in the NGA database of USA.The results show that the structural response tends to be enforced along with steady-state duration of the ground motion,and that the structural response will be enhanced when the earthquake energy focuses.There is a direct correlation between the influence of non-stationary characteristics of frequency on structural response and the change of the frequency with time,with the period of the latter part being significantly longer than the former part,significantly enhancing the structural response.The influences of the intensities and frequencies of ground motion on structural response are consistent under various constraints.更多还原