Digital image correlation application to a modular flexible floating structure

Abstract

In lab-scale model tests of modular floating structures, motion measurement is sensitive to mechanical influence of contact-based measurement systems. To investigate alternatives, model tests of a modular flexible floating structure interacting with regular waves was carried out in the towing tank of Delft University of Technology. Non-contact 3D digital image correlation (3D-DIC) technique was employed to evaluate the structural displacement. Stereovision based system Optotrak Certus of Northern Digital Inc., which relies on cable connection to the model, was used as a reference system to validate the DIC results. Model motions were analyzed and compared between the two systems. Comparisons show that DIC results agree well with stereovision results, indicating that the DIC system is an accurate motion measurement of floating structures in waves.