Research On The Mr Damper Control System And Experiment Of Shear-type Mr Damper

With continuous perfecting of Magnetorheological (MR) dampers' design theories, MR damper control technology attracted lots of attentions in the engineering fields. During the last few decades, extensive and deep studies have been performed on MR dampers' performance in control and engineering-oriented control system. Now it has been become a current research focus to design new-type MR dampers based on the existed valve-type and further investigate on yield shear strength testing of MR material.In this thesis, response property of a controlled MR damper is studied firstly and an engineering-oriented control system is designed. For stay cable's vibration control, a shear-type MR damper is proposed. A simple and effective equipment for the yield shear strength testing of MR fluid is put forward at last. Main contents of this thesis are detailed as follows:(1) Taking a linear viscous damper with initial friction as the objective, control test of the MR damper is designed and performed. It is found that at low frequencies MR can trace aimed control force well, but not at high frequencies due to the slow response of the damper.(2) For high efficient toolbox, algorithms embed in MATLAB and friendly graphical interface development of LabVIEW, semi-control system based on MR damper is designed by combing the two soft wares.(3) Taking advantage of structural simplicity of shear viscous damper and insensitivity of MR fluids'yield shear strength to temperature, a passive shear MR damper is raised. By either enlarging the shearing area or increasing the magnetic filed, it is easy to satisfy both the force requirement and size limitation of installing space for vibration control of stay cable.(4) In view of the defects of existing equipments for testing of MR fluids' shear strength, an instrument, novel and easy to use, is proposed. This instrument is used to test self-made MR fluid. Compared to the result tested by commercial equipments made by Anton Paar,it is showed that the precision of the new equipment introduced can satisfy the basic demands.