Carvalho, L. and Coraça, E., "Exploring Oberst Beam Standard Method for Viscoelastic Materials to Increase Test Confidence and Applicability," SAE Technical Paper 2017-36-0179, 2017.
Damping treatments can be employed to mitigate vibration levels of structures near a specific resonance frequency. In the automotive area, constrained-layer dampers are the most employed, consisting on a viscoelastic layer bonded to a metallic-restrictor layer and to the structure itself subsequently. The damper’s frequency performance is strongly dependent upon the temperature of operation, which means that there is a need to characterize this relation in order to choose the best damping material, thus optimizing the application. In this paper, a laboratory test procedure known as the Oberst Beam Method was employed to characterize the frequency and temperature behavior of a commonly used damper. The test, which involves the Frequency Response Function measurement of a system composed by the damper applied to a standardized beam, followed a SAE procedure. An auxiliary CAE model was also developed and compared to physical test results. As conclusion, modifications were proposed in order to improve results confidence and the applicability of the standard test in a laboratory environment.