Design And Research Of Passive Adaptive Magnetorheological Damper

Magnetorheological (MR) damper has become one of the most promising damping devices in structural vibration control fields because of its excellent properties. Currently, MR damper at home and abroad need coil and external power supply. It caused many problems, such as big size and weight, complex structure, dependence on energy, and stationary damping force when power off. Aiming at these problems, a passive adaptive MR damper was designed and made. Giant magnetostrictive material(GMM) was put into the damper. This kind of MR damper doesn't need coil and external power supply, so its structure is simple. It transformed the variation of load force into the variation of magnetic field through the damping channel based on magnetostrictive inverse effect and characteristics of MRF. and finally output different sizes of damping force, which show the characteristic of load adaptive.The detail work was presented as follows:(1) Analyzed the actuality and problems of MR damper at home and abroad currently; Put MRF and GMM together, according to applications and researches in GMM at home and abroad; Proposed the idea of designing a kinds of damper with load adaptive function.(2) In order to make passive adaptive MR damper has load-adaptive function, designed and simulated the magnetic field using magnetic field finite element analysis software, so that it can control the external magnetic field of MRF. Analyzed operating mode combining with the structure and work characteristics of ordinary MR damper. Designed the structure of passive adaptive MR damper according to the magnetic structure.(3) Established the model of magnetostrictive inverse effect based on Jiles-Atherton model, magneto mechanical effect and magnetic circuit law. Established and analyzed the model of magnetic structure which is constituted by permanent magnet, GMM, soft magnetic and MRF. Took test to verify the feasibility of the model. (4) Established the model for passive adaptive MR damper, according to Bingham constitutive model and fluid flow model of MRF.(5) In order to get the relationship between magnetic induction in damping channel and stress in GMM, and to verify the magnetostrictive inverse effect and the correctness of magnetic field design, static pressure test was taken for passive adaptive MR damper by the hydraulic universal testing machine; In order to research the damping characteristics of passive adaptive MR damper, dynamic test was taken by the MTS testing machine.