低频激振器楼面激振试验研究

本文对一座六层双向单跨的1:4钢框架模型进行土槽中低频激振器楼面激振试验,根据牛顿第二定律和作用力与反作用力原理,将激振器输出的信号转化为作用在结构上的动力作用,研究上部动力荷载作用下土与结构的动力相互作用。对采集的信号进行频谱分析和时域分析,研究体系的基频和模型顶层的加速度和位移反应,并与刚性地基上的结果进行比较。结果表明,土与结构的相互作用能有效降低体系的动力反应。考虑SSI效应时,大刚度结构对顶层加速度的削弱及位移的放大可能小于小刚度结构,这种削弱作用的大小主要是由结构的刚重比来决定。

Research on floor vibration test under excitation of low-frequency vibrator

The paper lays great emphasis on a test done on a six-storysingle-span 1:4 steel frame model.This is a floor vibration test subjected to the low-frequency exciter in soil tank.According to Newton’s second law and the principle of action and reaction,we study SSDI under dynamic load which is transformed from the signal vibration output.We do the spectrum analysis and the time domain analysis of signal acquisition,explore the systems baseband and the acceleration and displacement response at the top of the model,and then compare with those results obtained from a standardized method on a rigid foundation.The contrast shows that soil-structure interaction can decrease system’s dynamic response effectively.When considering SSI effect,the weakening of acceleration and the displacement amplification on the top of stiff structure may be weaker than the flexible structure,and the difference degree is decided by the ratio of rigidity to weight.