Application Of Magneto-rheological Damper In Ship Vibration And Noise Control

Usually, the structural parameters of damping devices commonly used on ships are set in a particular environment, which can not change with the surrounding environment. Consequently, the traditional damping devices have its constraints in application. With respect the above problems, a new type of smart magneto-rheological damper damping devices is proposed and used in ship vibration reduction, which is applied in combination with the traditional damping devices, resulting in controlling the vibration of ship in an optimum state.The main contents of the current paper are as follows:(1) Introducing the composition of the magneto-rheological materials and comparing the characteristics of magneto-rheological material. At the same time, the studies related to magneto-rheological fluid damper and magnetorheological elastomer damper are reviewed, giving the analysis of magneto-rheological damper in ship engineering application prospects.(2) According to the properties of magneto-rheological elastomer and referring to the existing magneto-rheological elastomers device design, a new type of marine magneto-rheological elastomers smart damper is designed. The characteristics of the smart magnetorheological elastomer damper are analyzed using the numerical method, concluding that this new type of magnetorheological elastomer damper has many advantages over traditional dampers. Furthermore, a new approach of designing the magneto-rheological elastomers is proposed based on numerical simulation.(3) The smart vibration reduction controlling system used in ships is composed of the new MR design in this paper in combination of traditional magnetorheological elastomer damper. At the same time, the principle of vibration reduction is illustrated and the arrangement in ships is designed in the present paper. Furthermore, by the comparisons between simulated and theoretical results, the validity and feasibility of numerical simulation employed in the field of ship vibration reduction is validated.(4) The application of magneto-rheological damper damping system which is mainly composed of MR is studied firstly. By the analysis of a series of simulations under various values of constant current, the responses characteristics of the MR damper under the same harmonic excitation force is obtained in a typical ship cabin, verifying the control effect of magneto-rheological damper device applied to the ship hull.(5) From the views of the ship hull structure, the approaches of solving the intense vibration of the frame in the frequencies varies from 100HZ to 150HZ are discussed from the aspects of structural stiffness and damping. The influences of vibration reduction are analyzed by changing the thickness of the plate, adding the stringers and as well as laying up the damping layer.