Development of magnetorheological fluids within 3D printed elastomeric cellular structures with an accumulator

In this study, a magnetorheological fluid (MRF) was encapsulated in a 3D printed cellular elastomeric encapsulant. Mechanical properties, such as stiffness and damping, of the encapsulant containing MRFs can be controlled via applied magnetic field. Such tunability can be exploited for adaptive vibration control or energy absorption systems. Here, MRF prepared with silicon oil (40% volume fraction) was injected into the 3D printed thermoplastic polyurethane (TPU) cellular encapsulant. The wall adjacent to the sealing layer had a circular opening and a TPU membrane was bonded to its perimeter so that the pressurized MRF could flow through the opening and be accumulated in the resulting pocket. An external magnetic field (0–350 mT) was applied to the sample at the time of uniaxial dynamic testing with 5% pre-strain. The MRF-TPU composites were characterized via cyclic force-displacement tests (1 Hz) under displacement amplitudes. The area of the force-displacement curve of the system with an accumulator is about 26% greater than one without an accumulator. The effect of the accumulator on the mechanical properties of the MRF-TPU composites was studied with strain amplitude and magnetic fields.