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

Abstract

A 3D analytical model is formulated for diffuse sound field transmission control through a smart hybrid double concentric sandwich circular cylindrical shell structure in presence of external and internal air gap mean flows. The multi-input multi-output sliding mode control is applied to enhance the sound transmission loss characteristics via direct control action of a uniform force piezoelectric actuator layer along with semi-active variation of the stiffness/damping characteristics of the electrorheological fluid core layer incorporated in a non-collocated configuration within the external or internal shell structure. Extensive numerical simulations examine the uncontrolled/controlled diffuse field sound transmission loss spectrums in a broad frequency range for single-wall and hybrid double-wall sandwich shells at selected external and air gap Mach numbers. The proposed smart hybrid active/semi-active double-wall configuration is demonstrated to provide satisfactory overall acoustic insulation control performance with much lower operative energy requirements. Limiting cases are considered, and validity of the formulation is verified against the available data.

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

“…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. Hasheminejad and Jamalpoor [60] improved the diffuse STL across a smart hybrid double concentric sandwich circular cylindrical shell structure under internal and external air gap mean flows using multi-input multi-output (MIMO) sliding mode control (SMC). According to the hyperbolic tangent shear deformation assumption, Li et al [61] calculated the natural frequencies and STL of FG honeycomb sandwich plates.…”

Prediction of sound transmission loss of conical acoustic enclosure using statistical energy analysis and its experimental validation

“…In recent years, structural vibration and noise related problems for such structures have drawn more attention due to the acoustic environment exposed to these structures. Several analytical and experimental studies were conducted to investigate the sound transmission characteristics through flat panels (Davy, 2009; Oyelade, 2020; Putra and Thompson, 2010; Zhou and Crocker, 2010), and cylindrical shells (Darvish Gohari et al, 2020; Hasheminejad and Jamalpoor, 2021; Lee and Kim, 2002, 2003; Talebitooti et al, 2018; Zhang, 2020).…”