变阻尼层复合梁式动力吸振器性能研究

Characteristics of dynamic vibration absorber shaped by steel beam with variable cross section rubber layer

为了有效降低弹性结构的振动响应,提出了新型变阻尼层复合梁式动力吸振器结构形式。以典型弹性薄板为控制对象,基于导纳功率流方法建立了多个复合梁在多个点与板耦合的振动模型,进行了吸振的理论及实验研究。通过对单个复合梁吸振效果的仿真分析,验证了变截面复合梁式动力吸振器具有吸振频带宽、吸振效果好的优点,并形成了一种确定复合梁参数的方法。进而对多个复合梁组合吸振效果进行了研究,理论与实验结果一致表明:在同一点安装多个不同吸振频率的复合梁进行组合吸振,可以拓展吸振器的吸振频带;在相近的多个位置分别安装复合梁进行组合吸振,其吸振效果可近似等效为各单个吸振器吸振效果的线性叠加;多个复合梁对弹性薄板进行组合吸振,效果明显。从而说明了新型变阻尼复合梁式动力吸振器用于弹性结构的有效性和可行性,也表明了变阻尼复合梁式动力吸振器具有可扩展性强的特点。

To control vibration of elastic structure,a new type dynamic vibration absorber is introduced to study its effect on mitigating vibration energy of structure theoretically and experimentally.While the elastic plate is certified as object to be controlled,the vibration model of plate fitted with multi composite beam at multi point is established by theory of power flow.After research on effect of single composite beam in energy absorbing,a method to obtain parameters of composite beam is formed and the advantage of composite beam in dissipating energy is proved.At the same moment,multi composite beam combined to decrease the vibration energy of plate is studied,the simulation results and experimental data shows that composite beams whose model frequencies are different with each other fitted at one point on plate can expand the bandwidth of absorber.While multi composite beam fitted at different point which is close to each other,the absorption of its combination is approximately equal to the union of absorption of each absorber in combination.It is concluded that the composite beams,which have advantages of wide bandwidth,great absorption and excellent extensibility,is fit to control vibration of plate with great effect,and its validity and feasibility is testified.