The coated beam method has long been used extensively for investigating the dynamic elastic characteristics of vibration damping materials. With this method, the beam is coated with the damping material on one side, or on both sides, and the resonances of bending vibration of the metal and coated beam are investigated for the determination of the dynamic characteristics. It is known from the experiments that in the case of a relatively thin, or soft, coating the error in the result of the investigation may be very large. However, the technical literature to date has not been concerned at all with the mathematical analysis of the error for a be.am coated on one side, and the error analysis published for a beam coated on two sides cannot be considered complete. Therefore, a complete error analysis for both beams is discussed in this paper. Relationships and diagrams are given by which the error in the dynamic characteristics can be calculated. Moreover, a few measurement results are discussed that can be well explained on the basis of the error analysis performed.
I This is an extended version of the paper delivered at the 9th