Determination of the Complex Shear Modulus of Damping Materials by the Composite Beam Test Method : An Evaluation of Determined Values in Consideration of Effect of Bonding Adhesive Layer

Abstract

A method for determination of the complex shear modulus of damping materials is presented, which involves a torsional vibration test of an elastic rectangular rod bonded to layered damping materials on both sides. The value determined by means of this method must take into account the effect of the thin adhesive layers bonding the elastic and the damping material. This effect is evaluated by means of the five-layer theory accounting for the adhesive layers. The reliability of the determined values is considered in conjunction with the adhesive layer thickness and the material properties of both the adhesive and the damping material. Furthermore, instability of the determined values in the high-temperature range is discussed.