Analysis of Nonlinear Vibrations Using DIC and the Smoothed Harmonics Method

This work focuses on the development of a novel methodology to extend the application of low-frame rate stereo camera systems to the study of the dynamic behavior of components when nonlinear phenomena are considered. The approach overcomes the low frame rate limitation of cameras in cases of steady state periodic oscillations by making use of a new down-sampling technique, the Smoothed Harmonics Method (SHM). The SHM allows an accurate reconstruction of a down-sampled signal and thus has many possible applications. In this work it was applied together with a full-field measurement using DIC. In particular, the methodology was used to analyze the motion of a beam with nonlinear stiffness due to intermittent contact and loaded with harmonic excitation.