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Review on Unconstrained Layer Damping Treatment and Its Applications

M. Prasanth Kumar, P. Jyothi, N. Ramanaiah


The unconstrained layer damping is also called as free layer damping. It is formed by applying a damping material on the surface of a structure. This treatment was used to reduce and control the vibrations and noise in structures. This paper presents a review on unconstrained layer damping treatment on beams using different damping materials. The objective is to present various aspects and relative merits of unconstrained damping treatment use in various cases. The important considerations and application areas of this technique is discussed in this paper.



Vibrations, damping treatments, CLD, FLD, loss factor

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Reddy CR, Ganesan N, Rao BV, et al. The response of plates with unconstrained layer damping treatment to random acoustic excitation. part I: damping and frequency evaluations. Journal of Sound and Vibration. 1980;69(1):35–43.

Roy and Ganesan. The theoretical and experimental investigations on the damping effectiveness of partially applied unconstrained layer damping treatments on rectangular plates having central rectangular cutouts. 1993.

Lee DH, Hwang WS. Optimization of length for unconstrained viscoelastic damping layer of beams using fractional derivative model. AIAA journal. 2004;42(10):2167–21670.

Ramji Koona, Ganesh Kumar. P.V.S., and Ranganath. S. Optimization of Surface Damping Treatments for Vibration Control of Marine Structure. Proceedings of Experimental Analysis of Nano and Engineering Material Structures, pp. 747–748, 2007.

Hazard L. Design of viscoelastic damping for vibration and noise control, modeling, experiments and optimization [PhD thesis]. [Brussels]: Free University of Brussels; 2006. 228p.

Yi S, Ahmad MF, Hilton HH. Dynamic Responses of Plates with Viscoelastic Free Layer Damping Treatment. Journal of Vibration and Acoustics. 2008; 118: 362–367.

Gallimore CA. Passive viscoelastic constrained layer damping application for a small aircraft landing gear system [Master’s thesis]. [Blacksburg (VA)]: Virginia tech; 2008. 117p.

Cura F, Mura A, Scarpa F. Modal strain energy based methods for the analysis of complex patterned free layer damped plates. Journal of Vibration and Control. 2012;18(9):1291–302.

Ashish M. Dharme, Pravin P. Hujare. Analysis of Performance of FLD and CLD Technique. International Journal of Engineering Sciences & Research Technology, Vol. 3(7), pp. 340–343, 2014.

Pankaj R. Beldar and Kushare D.V. Analytical, experimental and numerical analysis of passive damping treatment of Butyl rubber. International Research Journal of Engineering and Technology, Vol. 3(5), pp. 15–20, 2016.

Chandran KV, Patil AP. The experimental modal frequency and damping estimation of viscoelastic material by circle fit method. International Journal of Current Engineering and Technology. 2016;6(6):2199–2204.

Jones D. Applied damping treatments: the damping of an element of a structural system is a measure of the rate of energy dissipation which takes place during cyclic deformation. 5th ed. New York: McGraw-Hill; 2002.

Amirali Sadeqi and Shapour Moradi. Vibration analysis of elastic beams with unconstrained partial viscoelastic layer. International Journal of Acoustics and Vibration, Vol. 23, pp. 65–73, 2018.

Prill O, Busch R, editors. Inter-Noise and Noise-CON Congress and Conference Proceedings; 2016 Aug; Germany. VA: Institute of Noise Control Engineering; 2016.

Prabakaran. B, Giovanni Ferrari and Marco Amabili. Identification of the viscoelastic response and nonlinear damping of a rubber plate in nonlinear vibration regime. Mechanical Systems and Signal Processing, Vol. 111, 2018.


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