Dynamic Analytical Model Containing Eddy-Current Effects for Response Time of Magnetorheological Clutch

Magnetorheological fluid (MRF) based clutches have been shown potential importance in terms of torque coupling and control applications. As a key performance indexes of magnetorheological (MR) clutch, response time of magnetic circuit was only qualitatively discussed from finite element analysis and experimental testing in previous studies. Response delay in magnetic circuit of MR clutch contributes primarily to eddy current effects in the solid magnetic core and MRF. A simple yet accurate analytical model containing eddy-current effect would be highly beneficial during the design stage to determine the impact of device geometric and material properties on dynamic performance of MR devices. Aim at this issue, based on the combination of the magnetic equivalent circuit approach and eddy current effects, a dynamic analytical model for response time of MR clutch is proposed for the first time. The proposed model is capable of accounting for device material and geometric properties and providing fast, yet accurate solutions. The experimental test and finite element analysis from frequency response are used to verify the feasibility of the proposed model. Moreover, the model has been implemented to investigate the influence of the design parameters on the response time of MR device. All taken together, the analytical model provides a comprehensive knowledge in optimizing design and performance prediction of MR devices.