回转壳体中波传播特性研究的频率-波数谱法

Wave Propagation Characteristics of a Shell of Revolution Using Frequency Wave Number Spectrum Method

基于快速傅里叶变换和最大熵谱法提出了一种频率 -波数谱法 ,并对某水下航行器尾部壳体的受激响应进行了分析 .运用这一有效方法 ,得到了振动波在该壳体中传播的波数、波速、波型和波的传播方向等重要信息 .针对壳体尾部模型的受激响应控制进行了试验研究 ,讨论了加强筋对振动传播的影响 .进一步用波动理论解释了加强筋的减振机理 .结果表明 ,采用当前的加筋方案对壳体结构的振动噪声控制。

A frequency-wave number spectrum method was proposed based upon fast Fourier transform and maximum entropy spectrum principle. The dynamic responses of the tail part of the shell of revolution attached to an underwater vehicle in certain excitations were investigated. The wave propagation characteristics such as numbers, velocities, types and directions of waves in the shell were predicted and behaviors of the structural vibrations were discussed. Furthermore, control of the tail part of the shell was studied and validated in experiment. Effect of reinforced stringers and rings on wave propagation of the shell was analyzed and mechanism of vibration depression was discussed by wave propagation theory. It is demonstrated by the numerical results obtained from the frequency-wave number spectrum procedure that the reinforcement scheme is quite effective to the control of vibration noise, sound propagation and dynamic strength of the shell structure.