Study On Vibration Reduction Of Viscoelastic Sandwich Plate In Stern Structure

With the rapid development of industry, engineering vibration problems have become increasingly prominent, and structural vibration control has been a study focus. With its excellent damping performance, the technology of the viscoelastic damping material has become an important mean of access to a wide range of applications in engineering, and in the field of ship vibration control, the viscoelastic damping material also plays an important role. Study on the damping properties of viscoelastic materials has risen to an important position, and the research has made rapid development in recent years.Viscoelastic sandwich plate is a main application form of viscoelastic material, which can translate mechanical energy into heat energy to reduce structural vibration by the shear deformation of damping layer.In this paper, the author regards the viscoelastic sandwich plate as the research object, and makes numerical calculation about the dynamic characteristics of viscoelastic sandwich plate by the large finite element analysis software ANSYS. Basing on the analysis, the vibration damping effect of viscoelastic sandwich plate board on the ship stern structure is analyzed.This article introduces the current research of viscoelastic sandwich plate,and to the viscoelastic material,briefly describes the basic characteristics, the energy essence, the mathematical model, the main performance index and the factors of damping properties. Then,the author expounds finite element kinetic equations of viscoelastic sandwich plate and several several commonly used finite element method. Under certain accuracy requirement,this article takes the moduli of viscoelastic materials as constant, without considering the time-temperature characteristics of modulus.This method can avoid the huge computation, and can be more suitable for the application in the engineering.In this paper, using modal strain energy method, the author analyzes the vibration performance of the viscoelastic sandwich. The natural frequence and loss factor of the viscoelastic sandwich are also calculated. The author respectively discusses the influence of the thickness, modulus of elasticity,density of the damping layer, the thickness of constrained layer and the board size to the natural frequency and loss factor of the viscoelastic sandwich plate, and get some valuable conclusions. Comparing the vibration response of the plate before and after damping treatment, the results show that the viscoelastic sandwich plate has a good damping effect.The article establishes the finite element model of a ship stern, and installs the viscoelastic sandwich plate in the hull plates which are on the top of propeller. The author calculates the vibration response of measuring point on the stern plate and upper deck before and after installing the sandwich plate, and makes a qualitative analysis to the damping effect of the ship stern structure which installs viscoelastic plate.The results show that the viscoelastic sandwich plate has some vibration reduction effect.