Shape and deformation measurement system by combining fringe projection and digital image correlation

Abstract

An optical measurement system, which is capable of simultaneously measuring surface profile and three-dimensional (3-D) deformation of small objects, has been developed by the combination of fringe projection and a two-dimensional digital image correlation (DIC) technique. In the proposed approach, it requires only one camera and one projector. The surface profile and out-of-plane deformation are determined by fringe projection with the phase-shifting method. The in-plane deformation is determined by comparing the surface texture of specimen before and after deformation with the DIC technique. A simple procedure is described which enables determination of texture image from phase-shifting images. As an application, the developed system was used to investigate the mechanical behavior of molded pulp material in micro-zone during tension testing.