Determination of the Complex Shear Modulus of Damping Materials by the Composite Beam Test Method : Evaluation of Determined Value Taken into Account for an Effect of Adhesive Layer Deformation

Abstract

In this paper, an exact theory for determining the complex shear modulus of damping materials is presentd, by employing a torsional vibration test of an elastic rectangular rod with damping layered materials bonded on both sides. In the previous studies, the value determined by means of such a method, the so-called Composite Beam Test Method, has not taken into consideration for the effect of thin adhesive layer deformation. The difficult task of evaluating such an effect is carried out herein based on the five-layer theory presented. Theoretical and experimental results indicate some characteristics such as the adhesive layer thickness and its mechanical properties to be applied in this method, in conjunction with the damping material constants. Furthermore, an error estimation of the value determined in the high-temperature range is discussed.