基于自由振动的钢弹簧浮置板阻尼比测试分析

Damping Ratio Testing of Steel Spring Floating Slab Based on Free Vibration

在钢弹簧隔振器正上方放置一个混凝土质量块,形成单自由度的质量—弹簧—阻尼系统,对单自由度系统的自由振动进行理论分析。采用锤击法进行激振,根据其自由振动衰减曲线,对钢弹簧浮置板进行阻尼比测试。同时分别对质量块施加大、中、小3种不同等级的锤击力,分析不同锤击力对阻尼比测试结果的影响。测试结果表明：锤击法自由振动可以较好地测试钢弹簧浮置板的阻尼比;采用自由振动法测试阻尼比时,自由振动波形间隔取2～4个较为合适;锤击力的大小对阻尼比的测试结果影响较小,试验时可不区分激振力的大小。

A concrete block is placed above the steel spring vibration isolator, forming a single degree system of mass-spring-damper, and then theoretical analysis of free vibration is made in this study. A hammering test is conducted to test the damping ratio of the steel spring floating slab according to its free vibration attenuation curve. And in order to analyze the influence of hammer force on damping ratio, three different levels of forces（large, medium, small） are impacted on the concrete block. Test results are shown as follows： the free vibration by hammering test is good to test the damping ratio of the steel spring floating slab; the free vibration waveform interval of 2 ～4 is relatively appropriate for determining the damping ratio with free vibration method; the magnitude of the force has a little impact on the testing result, making it acceptable to ignore the size of the exciting force in testing.