双层欧拉梁声子晶体弯曲振动带隙特性研究

为了探究新型低频减振结构,建立局域共振型声子晶体双层欧拉梁简化模型,基于平面波展开法计算其能带结构,通过有限元仿真得到振动传输曲线并验证其带隙特性。结果表明,反对称振动和对称振动能带形成带隙,两能带耦合导致部分非带隙频段仍存在振动衰减,这是单层梁不具备的优势。根据固有振型给出带隙起始、截止频率的计算公式,并研究了弹簧刚度等对带宽的影响。

Study on Bandgap Characteristics of Bending Vibration of Double-layer Euler Beam PhononicCrystal

To explore a new type of vibration-reduction structure in low frequency,a simplified model of locally resonant phononic crystal double-layer Euler beam is established.The energy band structure of the beam is calculated based on plane wave expansion method,and the band gap characteristics are verified by the vibration transmission curve obtained by finite element simulation.The results show that the bandgap is formed by the antisymmetric and symmetrical vibration modes,and some attenuation behavior in Non-bandgap bands is caused by the two coupling modes,which is not available for single-layer beam.The formulas for calculating the initial and cut-off frequencies of bandgap are given according to the natural modes,and the effects of spring stiffness on bandwidth are studied.