Effect of Magnetorheological Fluid Pockets Energization on Dynamic Response of MR-Laminated Beams under Impulse Loading

Laminated composite beams are being used for many applications due to their high strength to weight ratio. To enhance the performance of laminated composites under dynamic loading, Magnetorheological (MR) and Electrorheological (ER) fluids have been considered to be added as embedded layers/segments to the conventional laminated structures. The present work focuses on the dynamic behavior of laminated composite beams incorporating MR fluid pockets (referred to as MR-laminated beams) under impulse loadings. A modified layerwise displacement theory is employed to account for the varying fluidity of MR pockets along the thickness direction. Four configurations of MR-laminated beams featuring multiple MR pockets distributed through the thickness and along the length have been examined. A parametric analysis explores the impact of magnetic field strength, number and placement of MR pockets, and boundary conditions on the dynamic response of the MR-laminated beams. The changes in natural frequencies concerning the size and location of activated MR pockets have been explored. Time-response analysis is conducted for MR-laminated beams subjected to impulse loading, considering various sizes and locations of activated MR pockets. The investigation highlights the significant influence of the MR pocket's location and size on the vibration response of MR-laminated beams. It is realized that the total stiffness, mass, and activation energy can be optimized according to the desired dynamic response of the beams. The proposed configuration for MR-laminated beam, results in a beam with 7% reduction in total mass while exhibiting fivefold increase in the corresponding natural frequencies, 40% increase in damping and 40% reduction in maximum amplitude.