C. Shen

Bio: C. Shen is an academic researcher from Xi'an Jiaotong University. The author has contributed to research in topics: Sound transmission class & Composite plate. The author has an hindex of 5, co-authored 6 publications receiving 124 citations. Previous affiliations of C. Shen include Nanjing University of Aeronautics and Astronautics & Hong Kong Polytechnic University.

Theoretical model for sound transmission through finite sandwich structures with corrugated core

Abstract: Due to the promising applications of lightweight double-leaf structures in noise control engineering, numerous investigations have been performed to study the vibroacoustic properties of these structures. However, no attention has been focused on the vibroacoustic properties of finite double-leaf structures with corrugated core used extensively in constructing the hulls of bullet passenger trains. In the present paper, a theoretical model is developed to predict the sound transmission loss (STL) characteristics of simply supported double-leaf partitions with corrugated core. The boundary conditions are accounted for by writing the displacements of the face plates in a series form of modal functions. The model predictions are validated by comparing with existing experimental measurements. The vibroacoustic properties of the sandwich construction are examined and the physical mechanisms for sound transmission through the structure explored, including the phenomena of ‘coincidence resonance’ and ‘standing wave resonances’. The effects of structural links, structural dimensions, inclination angle of the corrugated core, as well as the thickness of face plates and core layer on the STL are systematically investigated.

Sound Transmission Loss of Adhesively Bonded Sandwich Panels with Pyramidal Truss Core: Theory and Experiment

Abstract: In this paper, an analytical model is developed to investigate sound transmission loss characteristic of adhesively bonded metal sandwich panels with pyramidal lattice truss cores based on 3D elasticity theory. Meanwhile, practical specimen is fabricated to conduct corresponding sound insulation experiment test via a standing wave tube method. The effective elastic constant of truss cores is derived using one homogenization theory on account of equivalent strain energy. It is found that satisfactory agreement is achieved between theoretical solutions and experiment results, and damping effect of adhesive bonding interface between facesheets and core has a great impact on transmission loss. Further parameter investigations demonstrate the significant effect of the elevation and azimuth angles of the pyramidal cores, which can be conveniently changed to tailor the acoustic performance of the sandwich panels in the whole frequency range.

Transmission loss of orthogonally stiffened laminated composite plates

Abstract: Sound transmission through laminated composite plates reinforced by two sets of orthogonal stiffeners is investigated theoretically. A layerwise shear deformable theory is used to model the vibration of the laminated composite face-panel; A governing equation of I section composite beam is introduced, which accounts for the extensional, flexural, torsional and their coupling effects. The Euler-Bernoulli beam theory and torsional wave equation are employed to describe the flexural and rotational motions of the rib stiffeners, respectively. The technique of Fourier transform is applied to solve the governing equations resulting in infinite sets of simultaneous algebraic coupled equations, which are numerically solved by truncating them into a finite range insofar as the solutions converge. The accuracy of the numerical solutions is checked by comparing the present model predictions with existing literature. The validated model is subsequently employed to quantify the effects of the spacing of the stiffeners and the stacking geometry of the laminated composite face-panel and stiffeners on sound transmission through the structure. It is demonstrated that both the stiffener spacing and the stacking geometry have significant influences on the sound transmission loss across the structure. The proposed theoretical model successfully characterizes the process of sound penetration through stiffened laminated composite plates, which should be much helpful for the practical design of such structures with acoustic requirements.

A review of the vibroacoustics of sandwich panels: Models and experiments

Abstract: This paper reviews the most significant works in literature about the acoustic behaviour of sandwich panels, starting from the first examples of multi-layered structures, comprising a series of dif...

A closed form solution for the dynamic response of finite ribbed plates

Abstract: A simple and closed form solution for the vibration response of finite ribbed plates to point force/moment excitations is presented in this paper. This solution shows that input mobilities of finite ribbed plates are bounded by the input mobilities of the uncoupled plate and beam that form the ribbed plate. It is found that point force input mobilities of a finite ribbed plate are controlled by the plate bending stiffness when the excitation force is more than a quarter wavelength away from the beam. The input mobilities are mainly dominated by the beam flexural stiffness when the force acts on or very close to the beam, and when the beam flexural stiffness is far greater than the plate bending stiffness. Similar result is found in the moment excitation case when the moment axis is perpendicular to the beam neutral axis (bending moment excitation). In contrast, the input mobilities of the ribbed plate do not vary much from that of the corresponding uncoupled plate when the moment axis parallels to the beam’s neutral axis (torsional moment excitation) where the input mobilities are mainly dominated by the plate bending stiffness. The reductions in plate kinetic energy due to beam insertions are discussed.