Design and Modeling of Array-Type MRF Support for Shallow Spherical Shell

A shallow spherical shell is a typical weak-stiffness aerospace structure, which is always expected to have less or no deformation in machining. To control the shell deformation, magnetorheological fluid (MRF) is introduced to support a shallow spherical shell since it has high controllability with the help of external magnetic field. To minimize shell deformation, adopted MRF support should be determined according to the varying loads, but the optimal MRF support has not been designed and modeled. In this paper, to generate magnetic field with controllable strength/region, an array-type MRF support device is parametrically designed first. To characterize the shell deformation process in array-type MRF support device, a sequential MRF support model is established. Based on the sequential MRF support model, the optimal magnetic field layout is modeled and furtherly calculated on FE platform. At last, shell deformation under optimal magnetic field layout was experimentally compared with other support conditions. Experiment results indicate that optimized array-type MRF support can effectively control the shell deformation within a tight tolerance range.