Study On The Vibration Properties Of The Shipbuilding Sandwich Plates

Sandwich plate structure has attracted extensive attention in many engineering manufacturing fields due to its superior mechanical properties,especially in the fields of Marine engineering and aerospace engineering.As a new type of plate structure,its typical structural characteristics are lightweight,simple form of plate frame,because some sandwich plate core layer is special material or structure,so the energy absorption performance is significant,and anti-fatigue,anti-corrosion,at the same time,high space utilization,and has the advantages of filtering,impact and vibration reduction and noise reduction.In shipbuilding,in order to simplify its complex structure because of the special arrangement of framework and plate,the Sandwich plate will effectively solve these problems.This paper mainly studies the sandwich plate and carries out simulation analysis.A large SPS hatch cover model well be established based on common steel hatch cover structure.The vibration performance of two kinds of hatch cover are compared and analyzed.The vibration statistics theory well be applied to the nonlinear analysis of sandwich structure with Kagome truss core and sandwich plate with a continuous isotropic core layer.The results well be used as a reference for ship anti-vibration protection design.The main research contents and relevant conclusions are as follows:(1)The vibration characteristics of stiffened plate,steel plate and sandwich plate were studied.The parameterization of sandwich plate was analyzed.The response amplitude of the sandwich plate is the minimum by the harmonic response analysis and power spectrum analysis.The optimal design scheme is obtained by changing the thickness of the sandwich plate,the thickness of the core layer and the elastic modulus of the core layer.(2)The equivalent SPS hatch cover is designed and its vibration is analyzed based on the steel hatch cover model.Under gravity,the strength and stiffness of the two hatch covers are similar,and the weight of the SPS hatch cover is reduced by 12%.The SPS hatch cover has the smallest response amplitude and superior damping performance based on harmonic response analysis and power spectrum analysis.(3)The response statistics of the transverse excitations,the transverse and the in-plane excitations are investigated respectively.The method of the moment differential equations is applied to determinate second order steady-state moment.The effects of the system parameters are examined by the Monte Carlo numerical simulations.The analytical results are verified by the numerical simulations.(4)At last,based on the Reddy third-order shear deformation theory,the mathematical model of the sandwich plate with a continuous isotropic core layer under lateral external excitation was established.Then,the dimensionless state equation was obtained based on the multi-scale method,and the amplitude-frequency response curve of the equation under 1:2 internal resonance was obtained.The fourth order Runge-Kutta method was used to prove the approximation of the analysis results.