Multi-scale Analysis And Optimized Design Of Laminated-MRE Bearings

In order to improve the vibration isolation performance of Mechanics and architecture, and compensate traditional vibration isolator for its different response to different exciting load, the magneto-induced material called magneto-rheological elastomer(MRE) is introduced in the field of vibration isolation. Based on the magneto-rheology of MRE, we design a small scale bridge bearing prototype called magneto-rheological elastomeric bearing(MREB). The proposed bridge bearing is able to change its lateral stiffness by the control of current input. It is known that current that flows in the bearing’s coil consumes a lot of electrical power. The shortage of electrical power also curtails the adjustable stiffness of MREB. Therefore, it is of great significance to enhance the bearing’s adjustability without extra electrical energy consumption. The main research content is as follows:1. The magneto-induced properties of MRE and some physical parameters that related to MRE are introduced. The mechanical structure of traditional bridge bearing and research status of MRE isolators are reviewed. The paper also investigates the modeling and optimization method of MRE bearing, and the contrast is taken between those methods to understand the limitation of present work, so we propose our research goal and content.2. At the beginning we proposed a laminated bridge bearing based on MRE, where the electromagnetic unit is attached. Then, according to the multi-scale theory, The microstructure of MRE is analyzed, including the effect of particle volume fraction, material modulus of particles and matrix on MRE’s modulus. Based on Mori-Tanaka method and magnetic dipole model, we build the magneto-induced model and zero-field model respectively. To analyze the mechanical structure and boundary conditions, we build the mechanical model of laminated MRE bearing.3. According to the magnetic saturation theory, we build the small-scale magnetic model for MRE. And The Garnett-Maxwell method is used to obtain the magnetic permeability of MRE. The input current and mechanical structure of MREB is considered to simplify the MREB as magnetic circuit, which is helpful to analyze the magnetic flux density inside MREB.4. Based on the multi-scale mechanical and magnetic model of MREB, we establish a comprehensive model to interpret the magneto-mechanical behavior of MREB. The MATLAB software is also used to simulate the lateral stiffness of MREB and its adjustable range at different particle volume fraction, in order to investigate the optimal volume fraction which balances the relation between input power and MREB’s performance. and we predict the optimal volume fraction for the MREB5. We prepare the three types of MRE with different volume fractions and manufacture the MREB prototype. The test system is also designed to examine the examine the hysteresis loop of MREB with different power input. The experimental data is processed to achieve the lateral stiffness of MREB and its adjustable range. And the experiment results match well with the simulation consequences.