16 Nov 2020

Magnetorheological Composite Materials (MRCMs) for Instant and Adaptable Structural Control

Abstract: Magnetic responsive materials can be used in a variety of applications. For structural applications, the ability to create tunable moduli from relatively soft materials with applied electromagnetic stimuli can be advantageous for light-weight protection. This study investigated magnetorheological composite materials involving carbonyl iron particles (CIP) embedded into two different systems. The first material system was a model cementitious system of CIP and kaolinite clay dispersed in mineral oil. The magnetorheological behaviors were investigated by using parallel plates with an attached magnetic accessory to evaluate deformations up to 1 T. The yield stress of these slurries was measured by using rotational and oscillatory experiments and was found to be controllable based on CIP loading and magnetic field strength with yield stresses ranging from 10 to 104 Pa. The second material system utilized a polystyrene-butadiene rubber solvent-cast films with CIP embedded. The flexible matrix can stiffen and become rigid when an external field is applied. For CIP loadings of 8% and 17% vol %, the storage modulus response for each loading stiffened by 22% and 74%, respectively.