负泊松比超材料减振结构设计与实验验证

A Vibration Attenuation Structure Based on Negative Poisson Ratio Metamaterial and Its Experimental Validation

旋转机械的转子部件发生故障时,振幅会迅速增大甚至发散,此时需要一种轻质高效的吸能减振结构,快速控制转子部件的振动幅值.本文基于负泊松比材料概念,提出了一种针对转子系统的负泊松比弧形超材料减振结构,可以实现很好的故障转子减振效果.首先,通过释放自由度提出了负泊松比非对称星形胞单元,设计了针对转子的超材料减振结构,并给出了相应的能量吸收指标.然后,基于有限元模型进行了动力学仿真,讨论了不同冲击速度、不同冲击角度对能量吸收性能的影响.结果表明,低速冲击下,材料主要产生弹性变形吸能.随着冲击速度增加,材料变为弹塑性变形混合吸能模式,有效吸能率会明显增大.特别是在冲击速度较大时,减振结构的吸能率会迅速增加,这对于转子突发故障的减振十分有利.最后,设计了验证实验,对故障转子进行了负泊松比减振结构的验证实验.实验结果证明,对于转子的不平衡故障响应,设计的减振结构能够起到很好的抑制转子振动与吸收振动动能效果.

For rotor components in a rotating machinery,if there occurs a fault,the rotor’s vibration will increase rapidly and even result in serious damage.So the rotor needs a type of vibration energy absorption structure that has the feature of light weight and high energy absorption ratio.In this study,based on the negative Poisson ratio(auxetic)metamaterial,we propose an asymmetric star unit cell with negative Poisson ratio,and then design an arc-shaped vibration attenuation structure suited for the rotor system.First,the unit cell of negative Poisson ratio is proposed and the metamaterial vibration attenuation structure is designed.Then,the collision model is established and corresponding simulation is carried out.The influences of some key parameters are investigated,e.g.,the impact velocity and impact angle.It is found that for the low impact speed,the large impact angle will lead to a good energy absorption ratio;for the medium impact speed,the small impact angle will give a good energy absorption.Especially,for the high impact speed,the structure experiences plastic deformation and can reach a high energy absorption ratio.Finally,corresponding validation experiment was carried out on a rotor setup.For a rotor with two disks,the imbalance fault is produced.The experimental results show that the proposed negative-Poisson-ratio structure can attenuate the rotor vibration significantly,and absorb the vibration kinetic energy effectively.