Research On Vibration Isolation And Shock Resistance Of Vibration Isolation System With Displacement Restrictors For Warships

Warships were inevitably attacked by enemy weapons such as mines and torpedoes in combat.The resulting underwater non-contact explosion shock loads may cause large-scale failure of ship equipment,resulting in the loss of combat power and vitality of the warship.Therefore,vibration isolation devices were used of shipboard equipments when the warship designed.Due to the low natural frequency of the isolator,the attachment piping system damaged when shipborne equipment produces large relative displacement under the shock load.Therefore,limiters were installed on the equipment to limit the relative displacement of the equipment.However,the problem was produced that the shipborne equipment was subject to more severe secondary shocks.In order to improve the shock resistance of the shipborne equipment and improve the secondary impact of the traditional limiter,firstly,the actual installation of limit isolation device was simplified appropriately,and a physical model of the eight-parameter independently set limit isolation system was proposed.,three simulation calculation models were established by means of MATLAB,ANSYS and ABAQUS software respectively,and the accuracy of the calculation model was verified by the same example.Then,through the simulation calculation,the stiffness parameters,damping parameters,installation clearance and the natural frequency of the system were analyzed in order to influence the impact performance and vibration performance of the vibration isolation system.The following important rules were found:(1)For any isolation system,when the stiffness ratio is greater than 16,there is a special gap so that the acceleration response at this time reaches the maximum value,which is called the “resonance gap” and gradually increases as the stiffness ratio increases.Avoiding “resonance gap” is the best choice when designing the limit isolation system;(2)For an arbitrarily determined stiffness ratio,there is an optimal damping ratio that minimizes the acceleration response of the isolation system,and the optimal damping ratio increases with the increase of the stiffness ratio.When designing the limit isolation system,it should be The isolation system operates near the optimal damping ratio;(3)Increasing the damping of the limiter to the right of the optimal damping ratio,not only the relative displacement can be effectively limited,but also the isolation system acceleration response can be greatly reduced,the buffer coefficient is greatly reduced and the shock resistance of the system is improved,which has considerable research value.Finally,the test device for the limit vibration isolation system was designed,and the vibration test and impact test were carried out to verify the simulation calculation law.At the same time,in order to further study the influence of the large damping limiter on the impact response of the isolation system,the double-outlet rod-type hydraulic limiter was introduced into the shipboard equipment isolation system for the first time as a limit device.Firstly,the simulation calculation model of hydraulic limit vibration isolation system based on AMESim was established,and the influence of hydraulic limiter parameters on the shock response characteristics of vibration isolation system was analyzed.Then,the fourth-order Runge-Kutta numerical method was used to carry out the impact simulation calculation.Finally,the impact response characteristics of the hydraulic limit and rubber limit vibration isolation system were verified by impact test.The research results show that under any impact load,compared with the infinite isolation system,relative displacement response peak is reduced by at least 50% when using hydraulic limit,the limit effect is better,and the limit effect is better.Compared with the rubber limit isolation system,the relative displacement is guaranteed.Under the condition of consistent response,the peak value of the acceleration response is reduced by more than 70%,and the buffer coefficient is greatly reduced,which effectively improves the secondary impact and greatly improves the shipboard equipment.Therefore,and research designing a hydraulic limiter suitable for shipboard equipment isolation system has broad research value and application prospects.