Nonlinear dynamic response and stability analysis of electro-magneto-active circular membranes

Abstract

Electro-magneto-active membranes (EMAMs) represent a promising class of soft active materials capable of undergoing large deformations in response to coupled electrical and magnetic stimuli. Their unique ability to combine flexibility with multifunctional actuation has attracted significant attention for applications in soft robotics, biomedical devices, adaptive structures, and smart actuators. Despite these advantages, a comprehensive understanding of their nonlinear dynamic behavior and stability under coupled electro-magneto-mechanical loading remains limited. This thesis addresses this challenge by developing continuum mechanics-based models within the framework of the Gent hyperelastic constitutive theory to investigate the dynamic response and stability of reinforced electro-magneto-active circular membranes. The study first examines the influence of particle reinforcement on the dynamic behavior of EMAMs. The effects of filler volume fraction, shear modulus ratio, electric field, and magnetic field are systematically investigated under both DC and AC loading conditions. Time-history responses, phase portraits, Poincare maps, and frequency-response analyses are employed to characterize periodic, quasi-periodic, and chaotic oscillations. The results show that increasing particle reinforcement enhances the membrane stiffness, suppresses oscillation amplitudes, shifts the resonance frequency, and significantly improves the overall dynamic stability.