scispace - formally typeset
Search or ask a question
Topic

Constrained-layer damping

About: Constrained-layer damping is a research topic. Over the lifetime, 795 publications have been published within this topic receiving 15758 citations.


Papers
More filters
Patent
22 Dec 2009
TL;DR: In this paper, a hollow in-the-ear (ITE) hearing instrument shell is formed, and a port is created in the wall of the shell, adapted to interface the air space to an area outside the shell.
Abstract: Disclosed herein, among other things, is a system for constrained layer damping for hearing assistance devices. According to various embodiments, a hollow in-the-ear (ITE) hearing instrument shell is formed. The shell has an air space within a wall of the shell, in various embodiments. A port is created in the wall of the shell. The port is adapted to interface the air space to an area outside the shell, in an embodiment. A viscous fluid is dispensed into the air space via the port, and the viscous fluid is cured within the air space. The cured fluid acts as a constrained layer of mechanical damping within the wall of the ITE shell, reducing audible feedback to a wearer of the ITE.

12 citations

Journal ArticleDOI
TL;DR: In this paper, a modal constrained layer damping system constructed utilizing these elastomers exhibits its potentiality to attenuate structural vibrations with respect to mild steel bare plate resonator under laboratory fabricated testing methodology.
Abstract: Vibration damping properties of elastomers prepared from linseed oil were characterized by dynamic mechanical analyzer in a temperature range of 250 to 100 � C and frequency range of 5 Hz to 1 kHz. The maximum damping loss factor, tan d ðÞ max varies from 0.78 to 1.32, the room temperature (25 � C) loss factor, tan d ðÞ rt in the range of 0.56-1.08 and the temperature range (DT) for effective damping tan d � 0:3 ðÞ varies from 63 � C to 74.4 � C in different elastomers. The elastomers behave as a good vibra- tion damper both in lower and higher frequency range. Thus these elastomers exhibit good damping behavior in a wide range of temperature and frequency, a primary requirement for practical damping applications. A modal constrained layer damping system constructed utilizing these elastomers exhibits its potentiality to attenuate structural vibrations with respect to mild steel bare plate resonator under laboratory fabricated testing methodology. V C 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 3611-3623, 2013

12 citations

Journal ArticleDOI
TL;DR: In this paper, the authors investigated the nonlinear damped transient response of functionally graded carbon nanotube (CNT)-reinforced magneto-electro-elastic (FG-CNTMEE) shells using finite element methods.
Abstract: In this research work, the nonlinear damped transient response of functionally graded carbon nanotube (CNT)-reinforced magneto-electro-elastic (FG-CNTMEE) shells are investigated using finite element methods. The controlled response is obtained through active constrained layer damping (ACLD) treatment composed of a 1–3 piezoelectric (PZC) patch and the viscoelastic layer. The FG-CNTMEE shell subjected to different forms of load cases including mechanical and electro-magnetic loads are considered for evaluation. In addition, the influence of open circuit and closed circuit electro-magnetic boundary conditions on the damped transient response of the FG-CNTMEE shell is investigated for the first time in the literature. The equations of motion are derived using the principle of virtual work. The solutions are obtained through the condensation approach and the direct-iterative method. Several numerical examples are presented to assess the influence of parameters such as shell geometries, CNT distribution pattern, CNT volume fraction, and boundary conditions. Special attention has been paid to understand the effect of coupling fields on the damped response of the FG-CNTMEE shell.

12 citations

Journal ArticleDOI
TL;DR: In this article, the numerical Laplace transform is applied to the previous model, which was based on Fourier transforms, and the equations of motion of the system and the viscoelastic properties of the core are formulated in the Laplace domain.

12 citations

Journal ArticleDOI
TL;DR: In this article, the authors evaluated the performance of constrained layer damping for low frequency vibrations of cylindrical composite specimens made of glass fibre-reinforced plastics and found that the highest damping is achieved when placing the damping layer in the neutral plane perpendicular to the bending load.
Abstract: Constrained layer damping treatments are widely used in mechanical structures to damp acoustic noise and mechanical vibrations. A viscoelastic layer is thereby applied to a structure and covered by a stiff constraining layer. When the structure vibrates in a bending mode, the viscoelastic layer is forced to deform in shear mode. Thus, the vibration energy is dissipated as low grade frictional heat. This paper documents the efficiency of passive constrained layer damping treatments for low frequency vibrations of cylindrical composite specimens made of glass fibre-reinforced plastics. Different cross section geometries with shear webs have been investigated in order to study a beneficial effect on the damping characteristics of the cylinder. The viscoelastic damping layers are placed at different locations within the composite cylinder e.g. circumferential and along the neutral plane to evaluate the location-dependent efficiency of constrained layer damping treatments. The results of the study provide a thorough understanding of constrained layer damping treatments and an improved damping design of the cylindrical composite structure. The highest damping is achieved when placing the damping layer in the neutral plane perpendicular to the bending load. The results are based on free decay tests of the composite structure.

12 citations


Network Information
Related Topics (5)
Vibration
80K papers, 849.3K citations
76% related
Finite element method
178.6K papers, 3M citations
71% related
Fracture mechanics
58.3K papers, 1.3M citations
71% related
Numerical analysis
52.2K papers, 1.2M citations
69% related
Rotor (electric)
179.9K papers, 1.2M citations
68% related
Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202310
202227
202123
202020
201927
201826