Magnetic-field-dependent sound transmission properties of magnetorheologicalelastomer-based adaptive panels

Abstract

A two-dimensional analysis based on the linear theory of elasticity in conjunction with theclassical structural damping model involving frequency-dependent complex material moduliis formulated for investigating the sound insulation characteristics of an arbitrarily thicksmart sandwich plate with a tunable magnetorheological elastomeric (MRE) core. Theeffect of applied magnetic field strength (0–0.8 T) on controlling the transmission loss of theadaptive panel is determined for two different kinds of magneto-sensitive rubber corematerials constrained by either soft or stiff skin layers in the audible frequency range of100–1000 Hz for all angles of incidence. Also, the sound transmission loss for aperfectly diffuse sound field with a Gaussian directional distribution of energy iscalculated. The numerical results reveal that, while application of the magnetic fieldhas no appreciable effect on sound transmission in the low frequency range (f < 300 Hz), it can lead to notable improvements (up to 15 dB) at intermediate to high frequencies,depending on the angle of incidence, the skin/core type and core thickness. Moreover, it isdemonstrated that, for moderate and high applied magnetic field strengths, there isan optimum intermediate value of core thickness parameter associated with thesilicon-rubber-based MRE material which leads to enhanced acoustic insulationperformance, especially at intermediate and high incident wave frequencies. Limiting casesare considered and good agreement with the solutions available in the literature isobtained.