Acoustic Radiation Suppression of a Truss Core Sandwich Panel Using Decentralized Resonant Shunt Damping

2020 ◽  
Author(s):  
Kongming Guo ◽  
Jun Jiang ◽  
Yalan Xu
Keyword(s):  
Sandwich Panel ◽  
Acoustic Radiation ◽  
Truss Core ◽  
Shunt Damping ◽  
Resonant Shunt

Bending and free vibration analysis of foam-filled truss core sandwich panel

2016 ◽  
Vol 20 (5) ◽  
pp. 617-638 ◽  
Author(s):  
MP Arunkumar ◽  
Jeyaraj Pitchaimani ◽  
KV Gangadharan
Keyword(s):  
Free Vibration ◽  
Vibration Analysis ◽  
Sandwich Panel ◽  
Closed Form Solution ◽  
Free Vibration Analysis ◽  
Element Model ◽  
Form Solution ◽  
Numerical Comparison ◽  
Truss Core ◽  
Foam Filled

This paper presents the studies carried out on bending and free vibration behavior of truss core sandwich panel filled with foam typically used in aerospace applications. Equivalent stiffness properties for foam-filled truss core sandwich panel are derived by idealizing 3D foam-filled sandwich panel to an equivalent 2D orthotropic thick plate continuum. The accuracy of the derived elastic property is ensured by the numerical comparison of free vibration response of 3D and its equivalent 2D finite element model. The derived stiffness constants were used in closed form solution to evaluate the maximum deflection of the continuum. The results show that the free vibration and static behavior of the sandwich panel can be enhanced in due consideration to the space constraint by filling foam in the empty space of core. The results also reveal that triangular core foam-filled sandwich panel deflects less compared to other cores. From the free vibration analysis, effect of filling foam is effective in cellular and trapezoidal core.

Effect of longitudinal deformation on wave propagation in truss core sandwich panel

2020 ◽  
pp. 095745652096488
Author(s):  
Sun Liang ◽  
Xiao Yougang
Keyword(s):  
Transverse Direction ◽  
Sandwich Panel ◽  
Sandwich Panels ◽  
Theoretical Models ◽  
The Other ◽  
Full Model ◽  
Longitudinal Deformation ◽  
Compressive Wave ◽  
High Frequencies ◽  
Truss Core

The longitudinal deformation has been ignored by most previous study on vibroacoustic behaviours of truss core sandwich panels. This paper investigates its effect by developing two theoretical models. One, named as full model, considers both flexural and longitudinal deformation of face sheets while the other, named as flexural model, incorporates only flexural deformation. By comparing free characteristic waves obtained from two models, one find that flexural model ignore two waves, that is, a compressive wave and a global flexural one. The ignored waves cause vibration in transverse direction even at high frequencies, and thus result in vibration peaks under forced vibration. Therefore the flexural model would underestimate the vibration response, and the longitudinal deformation of face sheets cannot be ignored during dynamic analysis of the sandwich panels.

scholarly journals Piezoelectric resonant shunt enhancement by negative capacitances: Optimisation, performance and resonance cancellation

2018 ◽  
Vol 29 (12) ◽  
pp. 2581-2606 ◽  
Author(s):  
Marta Berardengo ◽  
Stefano Manzoni ◽  
Olivier Thomas ◽  
Marcello Vanali
Keyword(s):  
Electrical Circuit ◽  
Practical Implementation ◽  
Mathematical Treatment ◽  
Negative Capacitance ◽  
Control Performance ◽  
Shunt Damping ◽  
Stability Issues ◽  
Resonant Shunt ◽  
Theoretical Results ◽  
Shunt Impedance

This article addresses piezoelectric shunt damping through a resonant shunt associated with negative capacitances. The main objective of this article is to provide guidelines for choosing the best electrical circuit layout in terms of control performance and possible stability issues. This article proposes general analytical formulations for the tuning/optimisation of the electrical shunt impedance and for the prediction of the attenuation performance. These formulations are demonstrated to be valid for all the possible configurations of the negative capacitances. It is demonstrated that the behaviour of the different shunt circuits can indeed be described by a common mathematical treatment. Moreover, the use of two negative capacitances together is shown to provide benefits compared to traditional layouts based on a single negative capacitance. The mentioned advantages relate to both stability and attenuation performance. The use of a resonant shunt with the addition of negative capacitances is finally proven to provide enough attenuation to even cancel eigenfrequency peaks in some cases. This article also analyses the main issues arising from the practical implementation of the negative capacitances. Finally, the theoretical results are validated through experiments conducted on a cantilever beam coupled to two piezoelectric patches.

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