Active damping of sound transmission through an electrorheological fluid-actuated sandwich cylindrical shell

Abstract

An exact model is proposed for sound transmission through a sandwich cylindrical shell of infinite extent that includes a tunable electrorheological fluid core, and is obliquely insonified by a plane progressive acoustic wave. The basic formulation utilizes Hamilton’s variational principle, the classical and first order shear deformation shell theories, the Kelvin–Voigt viscoelastic damping model (for the electrorheological fluid-core layer), and the wave equations for internal/external acoustic domains coupled by the proper fluid/structure compatibility relations. The Fourier–Bessel series expansions are used to arrange the governing (coupled) system equations in state-space form. The classical Sliding Mode Control law is then applied to semi-actively reduce sound transmission through the composite cylinder by smart variation of stiffness and damping characteristics of the electrorheological fluid-core actuator layer according to the control command. Numerical results present both the uncontrolled and controlled sound transmission loss spectra of the sandwich cylindrical shell at three angles of incidence for three distinct sets of material input parameters that represent the electric-field dependency of the complex shear modulus of the electrorheological fluid-core layer. The superior soundproof performance of electrorheological fluid-based sliding mode control system in avoiding the highly detrimental sound transmission loss dips occurring throughout the critical resonance and coincidence regions is demonstrated. Likewise, remarkable enhancements in the sound insulation characteristics of the electrorheological fluid-actuated structure utilizing the first or second electrorheological fluid material model are achieved within the stiffness-controlled region, especially at lower frequencies in near-grazing incidence situation. A number of limiting cases are introduced and validity of the formulation is confirmed by comparison with the available data.

Sound Transmission Loss of a Honeycomb Sandwich Cylindrical Shell with Functionally Graded Porous Layers

“…Ahmadi et al [57] analyzed the effect of different models of carbon nanotube distribution on the variation of acoustic transmission of FGM carbon nanotube-reinforced composite cylindrical shells using FSDT. Hasheminejad et al [58] performed STL through a sandwich cylindrical shell with electrorheological fluid core. Fu et al [59] indicated the effects of gradient index, porosity volume fraction, and porosity distribution type on the variations of STL of a FG porous cylindrical shell under nonlinear thermal loading.…”

Control of sound transmission into a hybrid double-wall sandwich cylindrical shell

“…Daneshjou et al (2018) applied a modal transfer matrix approach to study the effects of mean external and air gap flows on sound transmission through a double-wall thick cylindrical shell system based on the three-dimensional theory of elasticity. Hasheminejad et al (2020) used the sliding mode control (SMC) strategy for semi-active sound transmission control across an electrorheological fluid (ERF)-based sandwich cylindrical shell under oblique plane wave incidence.…”

Sound transmission control through a hybrid smart double sandwich plate structure

“…Alternatively, employing auxiliary interior sound sources (speakers) for low-frequency sound field cancellation in the active noise control (ANC) technique is rather bulky, intrusive, and expensive, where the structural vibrations essentially continue unaffected [6,7]. On the other hand, the inherent characteristics of smart piezoelectric materials [8–10], electro-rheological fluids (ERFs) [11–13], and magneto-rheological (MR) materials [14,15] directly integrated into the conventional structures as control actuators, along with sophisticated control algorithms and high speed digital computing devices, have made them suitable candidates for active structural acoustic control (ASAC) in distributed parameter systems. Furthermore, by adopting a hybrid design philosophy, one can concurrently benefit from the diverse characteristics of various classes of conventional actuation/absorption mechanisms which cannot be realized by using a single type of actuator/absorber system alone (i.e.…”

“…This will be accomplished, after rigorous development of the associated acousto-elastic model, by applying the computationally simple and intrinsically robust multi-input multi-output sliding mode control (MIMO-SMC) strategy [46–48] to the hybrid smart composite system. This way, the vibroacoustic response of the hybrid structure can effectively be suppressed through smart variation of the damping/stiffness characteristics of the spatially distributed ERF-core layer [11–13] in collaboration with the active uniform force piezoelectric actuator layer [34,49–51] according to the control commands. The proposed acousto-elastic model can be of great interest for sound control engineers seeking acoustic partitions with superior sound transmission loss characteristics [2,6,52].…”