Space-time FE-DIC for vibration measurement

International audienceThe aim of this study is to develop a new digital image correlation method for vibration measurement under harmonic excitation. The correlation problem is written as a minimization problem over the space-time domain. The unknown displacement is searched for as a product of space (modal shape) and time (harmonic) functions. It is shown that the mode shape (space unknown) is less sensitive to noise as time periodicity acts as a physical regularization. In addition, such a formulation allows to alleviate the tradeoff between framerate and image definition when using high speed camera, since it is possible to have a framerate lower than the analysed frequency