AN EXPERIMENTAL STUDY OF VARIABILITY IN DAMPING, FREQUENCY RESPONSE AND MODAL DATA

Accurate modelling of the damping in structures, along with the mass and stiffness properties, is important for an accurate prediction of the dynamic response. Also important is modeling of the variability in damping, along with the variability the mass and stiffness properties, from sample to sample if the variability of the dynamic response is to be accurately predicted. The present work is a part of the ongoing efforts in this direction. The objective of this paper is two-fold. The first is to study the variability of the damping factors of various modes of the test structure over its several samples. The second objective is to study the variability when the test structures are made up of different materials. An experimental study is conducted on beam samples of three different materials, Mild steel, Aluminum and Acrylic. Variability in frequency response functions (FRFs), modal data including variability of damping factors is quantified. The study offers some important insights into importance of modeling of damping uncertainty for making accurate structural dynamic predictions.