Determination of correction coefficient for dynamic modulus of elasticity obtained by analysing the frequency response of a clamped cantilever specimen

摘要

In most cases, the analyses and calculations performed by numerous authors dealing with the dynamic methods of determining the modulus of elasticity E were based on cases where the requirements resulting from the boundary conditions of analytical solutions were met in full. However, in the case of cantilever clamping, there is a problem of how to realize the rigid clamping boundary conditions requiring zero flexure and the incline of the specimen in the clamping region. When calculating a dynamic module, it is therefore necessary either to take into account – in the case of low clamping ratios – a correction factor depending on the test sample, or to clamp the test sample so as to provide for a greater ratio of the sample free length to thickness. In our case, the error in calculating the modulus of elasticity decreases from 20% at the clamping ratio of 18 to just 5% at the clamping ratio of about 100.