Improved magnetic circuit analysis of a laminated magnetorheological elastomer devices featuring both permanent magnets and electromagnets

As an essential and critical step, magnetic circuit model is usually implemented in the design of efficient and compact magnetorheological (MR) devices, such as MR dampers and MR elastomer isolators. Conventional magnetic circuit analysis simplifies the analysis by ignoring the magnetic flux leakage and magnetic fringing effect. These assumptions are sufficiently accurate in dealing with less complicated designs, featuring short magnetic path lengths such as in an MR damper. However, when dealing with MR elastomer devices, such simplification in magnetic circuit analysis results in inaccuracy of dimensioning and performance estimation of the devices due to their sophisticated design and complex magnetic paths. Modelling permanent magnets also imposes challenges in the magnetic circuit analysis. This work proposes an improved approach to include magnetic flux fringing effect in magnetic circuit analysis for MR elastomer device. An MRE-based isolator containing multiple MRE layers and both a permanent magnet and an exciting coil is used in this paper as a case study. The results are compared to those of conventional magnetic circuit modeling and finite element analysis to demonstrate the effectiveness of the proposed approach.