Analysis Of The Dynamic Characteristic And Sound Radiation Of The Periodic Array Flexible Structure

With the development of science and technology, materials are often required to have multifunctional properties in the field of science and engineering. A periodic array flexible structure is a new type damping structure aiming to low frequency noise reduction. It has good damping characteristics, long fatigue life, and devisable structure etc. And also, it has a broad application prospect in the aerospace, aviation, navigation and other fields.In this thesis, dynamic mechanical properties of the flexible structure are analyzed by using sine force incentive method. The acoustic radiation of the single structure and the periodic array structure is calculated. First of all, this thesis analyses the dynamic characteristics of the first proposed structure model by using a finite element analysis software ANSYS; Secondly, by using ANSYS and numerical analysis software MATLAB, combines with the movement and boundary conditions satisfied by the second structure model, the equivalent mathematics model, which describes the liquid movement in the structure, is established, and the dynamic characteristics of the structure are analyzed. Thirdly, by means of continuous modification of the size of the two structures’parameters and dynamic analysis, the dynamic characteristics curves are obtained by fitting, as a result, the relational expression between the structure parameters and the transfer function is summarized. By utilizing these formulae, the dynamic characteristics of the structures can be precisely controlled or adjusted at low frequency. Finally, by comparing the complexity and dynamic characteristics controllability of the two structures, the infinite periodic array is arranged by using one of the above-mentioned structures, which has more advantages, and its acoustic radiation formula is derived, meanwhile the acoustic radiation characteristics of the infinite periodic array are calculated and analyzed.In a word, through theoretical derivation and numerical simulation, this thesis studies the dynamic mechanical properties of the two new damping structures, and calculates vibration and sound radiation of the second kind of structure. This study has a guiding significance to promote the research and application of flexible damping structures.