Design And Application Of Vibration Isolation Unit Based On Magnetic Induction Negative Stiffness Structure

Most engineering systems are excited by various kinds of vibration for a long time,so it is inevitable that the system will produce various vibration responses,and most of the vibration is harmful.The structure of large area and high precision Grating Ruling Engine is also called the king of precision,with high precision.Any small disturbance will have a very serious impact on it,which will greatly reduce its precision,so it needs to be isolated from the external vibration.In isolation technology,passive vibration isolation system has the advantages of no external energy,perfect development,low cost,and simple structure,which is more convenient than other isolation technology.However,the traditional passive vibration isolation structure has weak isolation ability for low frequency vibration.Based on the traditional passive vibration isolation,a parallel negative stiffness structure is proposed in this paper.The negative stiffness module is a combination of magnetic attraction induced negative stiffness and magnetic repulsion induced negative stiffness,so as to reduce the negative stiffness non-linearity,and then it is paralleled with the positive stiffness spring,which can greatly reduce the dynamic stiffness of the system without reducing the bearing capacity,so as to isolate the low-frequency vibration.The main research contents of this paper are as follows:(1)Firstly,we analyze the working environment of the Grating Ruling Machine,and determine that the source of the vibration factor in the working environment of the Grating Ruling Machine is pedestrian excitation,and then analyze the pedestrian excitation and establish a mathematical model.(2)Secondly,through the mathematical model of the interaction force between magnets,a reasonable stiffness model of the simple three magnet negative stiffness structure is established.Then,through the discussion and analysis of the reasonable ratio of the magnetic attraction induced negative stiffness and the magnetic repulsion induced negative stiffness,the correlation analysis of the size of the permanent magnet is carried out to pave the way for the selection of appropriate parameters.(3)Finally,according to the number ratio of magnetic attraction induced negative stiffness structure and magnetic repulsion induced negative stiffness structure and related structural parameters,the further optimization design is carried out to make the positive and negative stiffness parallel structure reach the quasi zero stiffness standard as far as possible.Finally,the dynamic model of the system is established,and the dynamic characteristics of the optimized structure are analyzed and verified by MATLAB simulation The feasibility of the optimized isolation model for low frequency vibration is proved.