SOME VIBRATION ISOLATION STUDIES USING CONSTRAINED LAYER DAMPING TREATMENTS WITH FRP COMPOSITES

  • Ranganath.B.A, Ramji Koona, Pramiladevi.M
Keywords: FLD, CLD, FRP Composites, Vibrations, RKU analysis.

Abstract

Uncontrolled vibration develops into a serious of problems in machinery and structures like the collapse of Tacoma Narrow bridge. Damping is the simplest method of control the vibrations by limiting the amplitudes and accelerations of the structure. Out of the two types of structural damping passive damping and active damping active damping involves complicated electronic gadgets and is suitable for highly sensitive structures. Structural damping in metals can be greatly enhanced by two passive damping techniques namely Free Layer Damping (FLD) and Constrained Layer Damping (CLD). In case of CLD the constraining layer thickness was optimized by Ross, Kerwin and Ungar (RKU) analysis. The constraining layer made of conventional metals increases the weight of the structure. Hence Fiber Reinforced Plastic (FRP) composite made of 70% epoxy and 30% E glass fibre were used as constraining layer as it is having higher complex Youngs modulus and shear modulus. Different beams were made using mild steel (MS), FLD by adding hard rubber as viscoelastic material and CLD using FRP composites as constraining layer. These beams were modelled using ANSYS and analyzed as per RKU method. Loss factor was calculated using OBERST beam technique and RKU equations. It was found that numerical analysis validates the experimental results. A constraining layer thickness of 2 mm of FRP composite increases the loss factor by 18.69% and reduces the frequency responses by 21%. In conclusion both FLD as well as CLD increases the loss factor and decreases the responses significantly CLD gives better performance.

Published
2021-08-15
How to Cite
Pramiladevi.M, R. R. K. (2021). SOME VIBRATION ISOLATION STUDIES USING CONSTRAINED LAYER DAMPING TREATMENTS WITH FRP COMPOSITES. Design Engineering, 8651-8665. Retrieved from http://www.thedesignengineering.com/index.php/DE/article/view/3409
Section
Articles