Basic Research On The Application Of Magnetorheological Fluid Technology In Microfluidic Inertia Switch

The traditional switch which is based on"sprin-mass"system has been applied to many applies, such as automobile srs, fuse and so on. Both of the electrodes of traditional switch are solid, which gives the switch many disadvantages,such as large contact resistance, easy to wear, contact instability and so on, which would reduce the performance of the switch.these disadvantages promote some new studies. MRF(magnetorheological fluid) is a kind of smart material which is widely used and has fine performance. MRF would have high viscosity if it is put in the magnetic field, so it has many applies, such as dampers, shock absorber and so on. In this article a new micro-inertial switch is introduced, which take MRF as its working-fluid; according to the new structure, a new MR fluid shear model is established, an experiment is designed to test the new model. in this article, the main study is focus on:1) According to environmental forces and the threshold required, a microfluid inertia switch design is introduced. Taking magnetorheological fluid damping force as the basis,a new structural is designed with the micro-channel liquid element. The MRF in the new structure has only one shear model, and the working-field is a rectangular solid.the new structure lower the difficulty of modeling then. Attention:the fluid in the magnetorheological damper and other inertia devices based on the viscous force of fluid always have to work on 2 mode at least, and should work in more complicated field.2) To build a new formula for computing the damping force. Taking the fundamental formula in fluid mechanics as the basis, superposing the fluid field, by the help of analyzing mathematics and matlab, to build the formula for computing the velocity distribution of the fluent field with different boundary condition step by step, at last to derive a new formula for computing the damping force after the moving plate getting an instantaneous impulse.3) To build an experimental platform according to the new formula for computing the damping forces. To design a experimental device by amplifying its size for reducing the error. By the result of experiment, to compare the new model with the traditional model, the result denote that the error based on the new model is lower than that of tradition.and the main error is because of the friction.4) To test the adaptability of the method of adding magnetic. By the help of ANSOFT and according to the final design of magnetic circuit, by the help of analyzing mathematics, to compute the Magnetic induction strength of magnetic field, and draw the curve of I-B.5) According to working condition of fuse and automobile srs, by the method of combine the mechanical structure with circuit control.to improve the function of switch and to improve the ability of distinguishing the force of environment of switch. The research suggests that the switch after being improved can distinguish the environmental force caused when the missile is launched from the environmental force when the missile is dropped from hathpace.