Investigation of Constrained-Layer Technique Using Exact Elasticity Theory

摘要

It is possible to damp flexural waves in metal plates by means of a layer of elastomeric material with high loss factor. It was found that adding a third layer of metal enhances the damping effect. This may be explained by observing that the constraining layer increases energy loss due to the loss factor in its shear modulus. The purpose of this research is to extend computational techniques by which one may decide on optimum combinations of layer thickness and material properties for a given damping application. A model proposed by Kerwin in 1959 shows the effect of the various parameters on the attenuation, but is uses thin plate theory for the base plate and does not account for extensional waves. Kerwin's model is extended to include extensional waves. A hybrid model is presented whereby the base plate is described by exact elasticity theory. Comparison of the results from the hybrid model with those of exact elasticity theory.