Experimental Modal Frequency and Damping Estimation of Viscoelastic Material by Circle Fit Method
Pages : 2199-2204
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Abstract
The main objective of the work is to estimate damping performance and shift in natural frequency due to coating of viscous-elastic material. The high performance damping material such as silicone, butyl rubber and Vinyl (PVC) are sandwiched with high stiffness materials like aluminum under constrained layer damping treatment. And synthetic rubber is sprayed and metallic hard chrome is electroplated on steel under the free layer damping treatment. The specimens are prepared according to ASTM standard E-756(05). The damping extends are measured by circle fit method in frequency domain by Impulse hammer test method and DEW-Soft Data Acquisition System. The results of empirical relations and experiments are compared. It is found that the butyl rubber and PVC has effective damping performance as compare to others and chrome has quite good strength without much compromise with damping.
Keywords: Modal frequency, VEM, Damping ratio, Circle-fit Method, Oberst Beam, Loss factor.
Article published in International Journal of Current Engineering and Technology, Vol.6, No.6 (Dec-2016)