截锥型薄壁结构声振耦合动力特性分析

采用大型通用软件ANSYS,建立截锥型薄壁结构的实体有限元动力学模型,通过与相关实验数据的对比验证了模型合理性。据此,利用无限元模拟自由声场边界,建立声场-截锥型薄壁结构的直接耦合有限元动力学模型。通过数值仿真分析研究了声场中截锥壳结构的振动特性,并讨论了声振动对结构动力特性的影响。研究结果表明:数值仿真结果和截锥壳声振实验数据比较一致。在考虑声场影响后发现:结构位移共振频率值大多有所降低,结构位移共振频率数量显著增多;在低频下,结构位移响应峰值在声场的影响下明显增大;在高频下则明显减小。

Dynamic characteristics analysis of a truncated conical thin-walled shell with acoustic-structure coupling

The 3D dynamic model of a truncated conical thin-walled structure is built using the ANSYS finite element software.The predicted results are in good agreement with the experimental data,thus validating the proposed model.The modeling involves solid finite elements for the structure and 3D acoustic elements for the sound field and the infinite elements for the free boundary conditions.The dynamic responses of the acoustic-structure coupling structure are investigated with numerical simulation approach.The effects of acoustic vibration on the structural dynamic characteristics are analyzed.The predicted results are found to be in good agreement with the vibro-acoustic test data.The number of resonant natural frequencies of the structure rises remarkably; their values decrease downward in most cases due to the effects of sound field.The amplitudes of the structural response increase in low frequency band and decrease in high frequency band.