结合波传播法和虚源法,提出了分析声吸收边界附近圆柱壳的固有振动特性的解析方法,并考虑了声吸收边界的影响.通过与有限元仿真方法进行对比分析,验证了方法的有效性.数值计算表明:与无限域中圆柱壳固有振动特性相比较,当圆柱壳靠近声吸收边界时,圆柱壳模态频率将明显减小;声吸收边界对圆柱壳模态频率特性的影响随着壳体与边界之间距离的增大而逐渐减小,当壳体与边界之间间距大于5倍半径时,声吸收边界的影响可以忽略.此外,当圆柱壳靠近声吸收边界时,边界的声反射系数对耦合系统模态频率特性有显著影响.
One method was proposed for free vibration of a submerged cylindrical shell near a soundabsorbing boundary with combination of the wave propagation approach and image method.The accuracy of present method was validated through comparison with the FEM.Numerical results show that the presence of sound-absorbing boundary will result in obvious reduction of coupled modal frequencies.And the effect of sound-absorbing boundary on coupled modal frequency will be reduced when the shell is far away.When the shell is more than 5time of shell radius away,the influence of soundabsorbing boundary can be neglected.When the shell close to the sound-absorbing boundary,the acoustic reflection coefficient makes big difference on coupled modal frequencies.