Analytical Model And Solving Method For Vibration And Acoustics Of Steel Sandwich Plate In Ship

Lightweight sandwich plate and shell structures is a kind of multi-functionalstructure, which has light weight, stiffness, energy to fight the strong performanceand good thermal performance, and many other fine features, so it has been widelyapplied in many areas. Marine polyurethane-steel sandwich panel is one of the plate.Nowadays, as a new sandwich board marine composites, it has been increasinglyused in the manufacture of various types of modern ships. Given its extensive andimportant applications, the problem of structural vibration and couple of acousticfield is make people pay more attention. In this paper, steel sandwich panel vibrationand acoustic problems are mainly talked in the following research:1、Research and summarizes several classic calculations model on the structureof sandwich panels. Summarizes Reissner type theory and the characteristics andbasic assumptions of the Hoff type theory and Du Qinghua type theory; Summarizingand gives equations and the general process of the SPSS static equilibrium using thesandwich plate Hoff type theoretical; Deriving the vibration equation of the sandwichunder Reissner type theory,and find a steel sandwich panel vibration frequencyexpression; Finally, compared the results of ANSYS calculation a numerical exampleis given to verify the correctness of the model to calculate the natural frequency of thestructure.2、The sound transmission characteristics of four edges simply supported steelsandwich plate was studied. Using the Reissner-type-theory of sandwich plateestablish vibration equation of acoustic vibration coupling theory model andcombining the condition of fluid-solid coupling obtain the control equation of theacoustic vibration coupling system.The incidence sound pressure,reflection soundpressure and transmission sound pressure are all shown by the form on the simplysupported modal double series,then bring them to the acoustic coupling equation andsolve it.And using the finite element software verify the accuracy of this theory.At thesame time,research for the influence of the elevation angle of the incidence soundpressure and the core layer thickness on the sound transmission loss.3，Research for the characteristics of the infinite steel sandwich panel underexternal force excitation radiation. Establish the theoretical model for acoustics-vibration characteristics of SPS in a uniform flow water. Apply for theconvection wave equation and the boundary conditions, consider the effect of theuniform flow, using Fourier wave number transform and stationary phasemethod,Obtained the displacement spectrum and analytic expression of acousticradiation. Using ANSYS to simulate this process, the results and calculation results ofthis model is more consistent. Finally, research for the fluid velocity of the uniformflow influence the acoustic radiation properties of SPS. The results show thatincreasing the fluid flow velocity can reduce SPS’ far-field acoustic radiation.