【摘要】 基于对10层配筋砌体结构模型进行的振动台试验,通过动力响应结果分析,得到NS方向随台面输入幅值的加大,顶层加速度反应的卓越频率并不直线下降,不同地震波输入对卓越频率的影响不大。当台面输入超过0.17g时,结构纵、横墙出现较多裂缝,非线性特性显著增加,卓越频率下降显著。随着台面输入的增加,放大系数并不显著下降,这显示出模型结构在中强地震作用下抗疲劳破坏能力较强。但放大系数对不同的地震波却较敏感,这反映了当输入地震动卓越频率与结构自身卓越频率接近时会有共振效应,模型变形模式以弯曲为主。从归一化频率与归一化输入地震动峰值的关系可以看出,从无输入到小震0.08g输入,频率下降较快,说明即使在弹性阶段,结构的固有频率也与受到激励的强度有很大关系,这使基于频率的结构完好状态判断带来很大困难。在中等破坏之前,频率缓慢下降,从中等破坏到严重破坏,频率又有显著下降。更多还原

【Abstract】 Based on the vibration table experiment of 10-storey reinforced masonry structure,the conclusion are made by analyzing the dynamic response results.It shows that dominant frequency of acceleration on top floor doesn’t decrease linearly with the increase of the table input amplitude in the direction of NS,hence the influence on dominant frequency doesn’t go with the various seismic wave input significantly.When table input is over 0.17g,many cracks can be observed on the longitudinal and lateral wall,the non-linear is more obvious,and the dominant frequency decreases obviously.But with the increase of the table input,magnification factor doesn’t drop much,which shows that model structure has the high resistance to fatigue damage.While,magnification factor is sensitive to seismic wave,which shows that resonant effect emerges when dominant frequency of input ground motion is similar to it of structure.Most bending deformation is observed on model.From the relationship of peak between normalized frequency and normalized input ground motion,fast decreased frequency can be concluded from no input to small input,which indicates that natural frequency of structure has great relationship with incentive intensity,and brings much difficult to estimate structure health condition.The frequency decreases slowly before moderate damage,however,significantly from moderation to seriousness.更多还原