Research On Dynamical And Sound Transmission Characteristics Of Sandwich Plate Based On Zig-Zag Model

Improve the acoustic stealth performance of naval ship especially submarine, beneficial to increase combat force and survivability. With the widely use of new material and technique in shipbuilding, sandwich plate structure had been widely accepted because of her excellent characteristic. Sandwich plate is a modem structure, which has been developed in recent years, and it has her specific characteristic, which was high stiffness, light, easily to design and quickly molded in contrast with isotropic material. On the other hand, it has its own disadvantage, such as anisotropy, hard to extend and complicated, which lead the mechanics to an intricate extend. As a result the study of sandwich plate plays an important role in its research and application. So it's necessary for us to study.Composite sandwich plate dynamic finite element model was established based on Zig-Zag deformation assumptions and Mindlin first order shear plate theory, three independent coordinate systems were established for upper face, down face and core respectively, parts of corners are independent, the finite elements equations of sandwich plate was established with computer codes, a more accurate finite element model was provided for dynamic analysis of sandwich plate with thick and soft cores. Applying modal analysis theory, the response of sandwich plate was calculated in time domain and frequency domain. A sandwich plate embedded in an infinite plate sound transmission calculation model is established using the coupled finite element /boundary element method. The dynamic character and the sound transmission losses through sandwich plate were calculated and discussed with the computer program of the proposed model in detail.Material and thickness of the core were considered for natural frequency, response and sound power excited by point force, material and thickness of the core were considered for sound transmission losses excited by plane sound waves and in sound diffuse field in the typical examples. The numerical results reveal the dynamic and sound transmission characteristics of sandwich plates, provide a basis to improve dynamic and acoustic characteristics, have a certain guiding significance for the acoustic design of sandwich plate.