基于内嵌式颗粒阻尼器的悬臂梁减振实验研究

Experimental investigation of cantilever beam vibration based onembedded particle dampers

针对悬臂梁结构振动控制问题,开展基于内嵌式颗粒阻尼(embedded particle damper,EPD)减振方法的理论与实验研究。应用有限元法分析悬臂梁振动特性,围绕梁前三阶模态频率开展振动控制实验,通过改变填充颗粒的参数(粒径、填充率)和激励力,比较悬臂梁在不同填充情况下的振幅,并使用半功率法计算阻尼比。采用离散元法分析不同情况下颗粒的流变行为,以确定阻尼器最优设计参数。结果表明:颗粒填充率为90%时EPD减振效果最佳;填充颗粒的粒径与系统所受激励有关,本文模型中,激励振幅为80μm时,梁前三阶模态频率下分别填充直径为8、6、1 mm颗粒时效果最好,减振率分别为47.5%、48.7%及71.2%,阻尼比分别提高1.7、3.1及2.1倍。

Theoretical and experimental researches on embedded particle damper(EPD)damping method were carried out for vibration control of the cantilever beam structure.The finite element method was applied to analyze the vibration characteristics of the cantilever beam,and the vibration control experiments were carried out under the first,second and third order modal frequencies of the beam.By changing the parameters of the filled particles(particle size,filling rate)and the excitation force,the amplitudes of the cantilever beam under different filling conditions were compared,and the damping ratio was calculated using the half-power method.The discrete element method was used to analyze the rheological behavior of the particles in different cases to determine the optimal design parameters of the dampers.The results showed that:the best damping effect of EPD was achieved when the particle filling ratio was 90%;the particle size of the filled particles was related to the excitation of the system.In this model,when the excitation amplitude was 80μm,the best effect was achieved when the beam was filled with 8,6,1 mm particles at these three modal frequencies,and the damping ratios were 47.5%,48.7%and 71.2%,respectively,and the damping ratios increased by 1.7,3.1 and 2.1 times,respectively.