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
Journal ArticleDOI
TL;DR: In this article, a free vibration analysis has been carried out on various viscoelastic sandwich beams like Al-NR-Al, Al-NeR-Al and MS-NRMS under four edge conditions viz., clamped-free, clamped - clamped and clampedsimply supported.
Abstract: Background/Objectives: Constrained Layer Damping (CLD) is an effective passive damping technique to suppress the vibrations using to analyze the vibration behaviour of viscoelastic sandwich beams. A Sandwich beam contains two face layers at top and bottom, one core layer of viscoelastic material. Methods/Statistical Analysis: In this paper free vibration analysis has been carried out on various viscoelastic sandwich beams likes Al-NR-Al, Al-NeR-Al, MS-NRMS and MS-NeR-MS under four edge conditions viz., clamped-free, clamped - clamped, clamped-simply supported and simply supported-simply supported. Analytical solutions are to be carried out using Euler-Bernoulli’s theory and Newton- Raphson method has to be adopted to investigate the natural frequencies of various sandwich beams. Findings: The beam’s natural frequencies for different mode numbers with face material as aluminium and core as polyurethane rigid for analysis of fixed free sandwich beam and observed that as mode number increases natural frequencies increases due to non dimensional number increases. And found that the higher natural frequencies obtained for clamped-clamped condition of Al-NR-Al sandwich model for various edge conditions such as conditions like clamped-free, clamped - clamped, clamped -SS and SS-SS. As mode numbers increase the modal behaviour shows diverging nature because of the effect of eigenvalue. The maximum percentage variation in natural frequency from fixed-fixed and fixed-free condition is 26.35. Improvements: The higher natural frequencies are obtained when mild steel is used as face material. The natural frequencies were reduced when neoprene rubber was used as core material.

5 citations

Proceedings ArticleDOI
01 Jan 1997
TL;DR: In this paper, a detailed stress analysis for a beam with the active constrained layer damping is conducted to prove the high stresses distribution at the interfaces, and then a simulation of crack growth along the interface is addressed.
Abstract: The reliability of a piezoelectrically controlled multi -layers composite structure is just as important as the performance. Since the piezoelectric layer may induce extremely high stresses to result in piezoelectric al/ mechanical failures, the safety design of the multi-layer composite structure should be fully emphasized. For this issue, first an intensive literature review is given to the general features of multi-layered composite structures. The local piezoelectric coupling induced stress is shown to have the magnitude proportional to the square of vibration mode number. A detailed stress analysis for a beam with the active constrained layer damping is conducted to prove the high stresses distribution at the interfaces, and then a simulation of crack growth along the interface is addressed.

5 citations

Journal ArticleDOI
TL;DR: In this article, the damping ratio of composite-rubber-composite sandwich beam with pristine composite beam having nearly the same flexural stiffness and range of frequency of vibration from 20 Hz to 100 Hz.
Abstract: Constrained layer damping is one of the passive techniques to control amplitude of vibration of structural components. In the present work an attempt has been made to quantify and compare damping ratios of composite-rubber-composite sandwich beam with that of pristine composite beam having nearly the same flexural stiffness and range of frequency of vibration from 20 Hz to 100 Hz. Length and thickness of sandwich and pristine beams in order to have the same flexural stiffness and desired frequency range of vibration were specifically designed. The damping ratio of each sandwich and pristine composite beams were measured experimentally using logarithmic decay and half-power bandwidth techniques.

5 citations

Journal ArticleDOI
01 Mar 2009
TL;DR: In this article, the effect of different thicknesses for the middle layer on the overall natural frequencies and modal damping factors are studied, and the governing equations are derived analytically by applying Newton's second law of motion for a three-dimensional elastic medium, and by employing complex elastic moduli for the sandwiched layer.
Abstract: Free vibrations of damped three-layer sandwich cylinders with thick layers are considered. In particular, the effect of the different thicknesses for the middle layer on the overall natural frequencies and modal damping factors are studied. The constrained-layer damping is accomplished by sandwiching a linear visco-elastic material between two isotropic elastic cylinders with the same properties. The governing equations are derived analytically by applying Newton's second law of motion for a three-dimensional elastic medium, and by employing complex elastic moduli for the sandwiched layer. Dimensionless natural frequencies and modal loss factors for the first three thickness modes associated with wave numbers of n = 0, 1, 2, 3, and 4 are tabulated for a range of thicknesses for the middle visco-elastic layer while keeping the thicknesses of inner and outer layers unchanged.

4 citations

01 Jan 2009
TL;DR: In this article, the authors investigated specific constrained layer damping applications for cantilever-loaded spring steel landing gear for a 386 lb. aircraft using available damping materials that have been tested to quantify loss factor.
Abstract: Aircraft design represents an optimization of structures and aerodynamics to meet weight, strength and reliability constraints. Included in this optimization is the landing gear system, which typically accounts for 3 - 7% of the total aircraft weight. For fixed gear designs, a significant amount of the total drag can be attributed to the landing gear, and so both reduction in weight and drag are priorities when designing a landing syster. The use of constrained layer visco-elastic damping on landing gear structural members is a new application since historic use of constrained layer damping has been found on thin plate-like structures. Benefits of low weight and low drag are achievable using the conformal treatment, and this paper investigates specific constrained layer damping applications for cantilever-loaded spring steel landing gear. Achievable damping levels are examined for a 386 lb. aircraft using available damping materials that have been tested to quantify loss factor. Results of the analysis show optimal constrained layer thicknesses for a variety of materials. Weight and aerodynamic drag are quantified for the landing gear with the damping treatment installed.

4 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