Experimental Investigations of Damping in Multilayered Materials

Damping characteristic of a material, also known as loss factor in dynamics, is challenging to estimate. However, the accurate determination of the damping value is critical in the prediction of vibration response and in the control of structural vibrations. While many studies have focused on the accurate measurement of the loss factor and other dynamic characteristics, there is a need for the study of factors controlling the damping and its variation. This work seeks to understand the variation of damping at a given point in a material and across the length and depth of material. The approach uses the time domain and a single frequency mode in all the configurations during the study. Different layered arrangements of composite beams are considered to study the influence of the layer configuration in the overall dynamic response. The study finds substantial damping variation at a single point, along the length of the samples and very little variation along the depth or thickness of the samples. The research also highlights the importance of the layers arrangements with the overlaying top layers materials governing the overall damping response of the layers. Keywords-Damping, Cyclic loading, layers, Vibrations, Dynamics