UNCERTAINTY IN THE ASSESSMENT OF YOUNG'S MODULUS AND THE LOSS FACTOR USING THE OBERST METHOD

The aim of this work is to quantify the uncertainty associated to the variation in the experimental determination of Young's Modulus (E), the loss factor (eta) of viscoelastics materials, using the methodology described in ASTM E-756 standard based on the Oberst theory. The first approach is to study how the results are affected due to small differences in the length and thickness of the reference Oberst beam. Furthermore, the obtained results are contrasted using two different transducers, the contact sensor (accelerometer) and the contactless sensor (magnetic). Finally, the associated uncertainties to the use of the damped one side (Oberst) and the damped both side (Modified Oberst) beam configurations are compared. The associated uncertainty will be also numerically studied using FEM (Finite Element Model).