Design And Application Of Variable Parameter Magnetorheological Isolator

In the feild of science and technology,the contradiction between the increasing hu-man living standard and the demand of mechanical vibration control is more and more prominent.A variable parameter semi-active control using magnetorheological(MR)tech-nology has been widely studied to improve the performance of vibration control.This paper studies the application of MR technology in the fields of variable mass system and micro-vibration control.And the corresponding MR dampers are designed and tested as the research achievements.The natural frequencies of the variable mass systems change at different load conditions,and the traditional passive vibration control method can not realize vibration control effect when the parameters of the vibration system change.In this paper,a non-piston magnetorheological(NPMR)damper is designed according to the vibration model of variable mass system and its vibration control performance is stud-ied experimentally.For controlling the micro-vibration,a double spring MR isolator is designed on the basis of variable stiffness and damping model,then its vibration control performance is studied.First of all,the suspension system of the automatic impeller washing machine which is a typical variable mass system,is studied for improving the vibration performance.The vibration mechanism of the washing machine is analyzed,meanwhile,the mathematic model and the vibration model of the washing machine internal tub are established.The dynamic simulation of the washing machine structure is carried out by the CAE software.According to the theoretical analysis,a NPMR suspension rod is designed,which comprises an air damper part and an MR damper part.Then,the experimental system of the MR suspension rod is built,including the damp-ing force experiment system of MR damper and the vibration control experiment system of the washing machine.According to the experiment and analysis of the experimental results,the NPMR suspension rod can achieve stable damping force output and realize good vibration control performance of the washing machine.When using NPMR suspen-sion rods,the vibration acceleration of the washing machine can be reduced to half of the original passive ones.A double spring MR isolator for micro-vibration control is also studied in this paper.The vibration control object is placed at the joint of two series elastic units by changing the vibration model based on the principle of variable stiffness and damping MR damper.The equivalent stiffness of the new vibration model is controlled by the damper.According to the improved vibration model,a double spring MR isolator is designed and the damping force of the outer MR damper and the internal MR damper is tested.Then the mechanical experiment of the MR isolator are carried out by using the shaker.The MR isolator can achieve the objective of vibration reduction by analysing the experi-mental results.The studying of the semi-active vibration control strategy,the vibration control of the variable mass system and micro-vibration environment require the variable-parameter characteristic as well as the appropriate control strategy to control the input current of the MR dampers.In this paper,the vibration control performances of the variable-parameter MR dampers are comprehensively studied from the aspects of the analysis,test and experimental study.