弹性接触层对双层柱壳中纵波传播特性的影响

Influence of elastic contact layer on longitudinal guided wave propagation in a double layered cylinder shell

基于弹性波理论,研究了轴对称纵波在具有较薄弹性接触层的双层中空柱壳中的传播特性。当接触层厚度远远小于波长时,忽略接触层的惯性运动,根据自由边界和弹性层接触界面条件,导出了轴对称纵向自由波传播的无量纲频散方程,利用数值方法求得频散方程的实数根,并将得到的频散关系与已有文献的计算结果对比,验证了该方法的正确性。通过算例分析了接触层参数对纵波第一模态相速度频散关系及壳体内应力、位移的影响,结果表明:波长越短接触层对频散关系的影响越为显著,同一波数条件下,相速度随着接触层厚度增大而增大;壳体内应力、位移随着接触层单位层厚刚度的增大而减小,但受接触层泊松比变化的影响不大。

Based on the elastic wave theory, the propagation characteristics of axial symmetric longitudinal guided wave in a double layered hollow cylinder shell with a thin elastic contact layer were investigated. When the contact layer thickness was far less than the wavelength and the inertial motion of the elastic contact layer was omitted, the dimensionless dispersion equations of axial symmetric longitudinal wave was derived according to free boundary conditions and elastic contact layer interface condition. The real roots of the disperse equations were solved with the numerical calculation method and the dispersion relation was obtained. The gained dispersion relation was compared with the results calculated in existing references, the correctness and effectiveness of the proposed method was verified. The influences of the contact layer on the first mode phase velocity dispersion relation of the longitudinal wave and the stress and displacement of the cylinder were analyzed with examples. The results showed that the shorter the wavelength, the larger the effect of the elastic contact layer on disperse relations; the phase velocity increases with increases in the contact layer thickness under a fixed wave number value; the stress and displacement decrease with increases in the stiffness of a unit contact layer thickness, while Poisson's ratio of the contact layer has little effect on them.