Experimental Research On Ship Vibration Reduction Mounting Based On MR Damper

Perfomance of vibration reduction is an important index that evaluates holistic performance of ship. Recently, the study on this area has become the hotspot. At the present time, most of the vibration absorber components in our country are passive model,for example, rubber damper, steel wire damper,etc. However the mechanical properties of passive absorbers are mostly changeless.But for ship equipments, their working frequencies are changing, it is necessary to apply controllable vibration absorber in the equipments vibration reduction for get the best effect. In order to solve this problem, this paper presents a new controllable mounting system, which is composed of intelligent power component and traditional ship absorber component in parallel. Based on this idea, the design of this mounting system is carried through using MR dampers and steel rope springs, and the characteristics of this mounting system were investigated by model tests. The results show that the damping capacity of MR damper is good in various frequency bands, especially in low-frequency. The damping effect is obviously better than traditional damping component.In this paper, the main work contents have been done as follows:(1)Based on the idea of putting the MR dampers and steel rope springs in parallel and taking the ship engine as protected object, an mounting system model is designed. The basement of traditional ship is altered reasonably according to the present shape characteristics of MR damper in our country.(2)The simulation analysis on steel rope spring and MR damper's characteristics were carried out. Calculated how the gap between piston and inner surface of cylinder effects the damping force of MR and how the aspect of steel rope spring effects its stiffeness. And determined the parameters of steel rope springs used in model test.(3)The simulation analysis on vibration responsies of mounting system were carried out. Software ANSYS was used to solve the vibration responses. (4)Vibration model test were designed based on the MTS multiplepoint loading system and LMS data-acqusition system. A lot of load cases were used in the test by changing exciting frequency, exciting force, mass of vibration system, corrent in MR damper. And at last, PID method was adopted to control the vibration response. The experiment results indicate that the mounting system has good effect on controlling structure vibration, especially for low frequency.(5)The model of MR damper was developed using Sigmoid model based on the charecteristicses of MR damper in model test. The physical significiance of parameters in this model are more clear and the equation is simple.