Force Identification Based on Response Signals Captured with High-Speed Three-Dimensional Digital Image Correlation.

Structural Health Monitoring (SHM) systems allow three types of diagnostic tasks to be performed, namely damage identification, loads monitoring, and damage prognosis. Only if all three tasks are correctly fulfilled can the useful remaining life of a structure be estimated credibly. This paper deals with the second task and aimed to extend state-of-the-art in load identification, by demonstrating that it is feasible to achieve it through the analysis of response signals captured with high-speed three-dimensional Digital Image Correlation (HS 3D-DIC).

Full-Field Indentation Damage Measurement Using Digital Image Correlation.

A novel approach based on full-field indentation measurements to characterize and quantify the effect of contact in thin plates is presented. The proposed method has been employed to evaluate the indentation damage generated in the presence of bending deformation, resulting from the contact between a thin plate and a rigid sphere. For this purpose, the 3D Digital Image Correlation (3D-DIC) technique has been adopted to quantify the out of plane displacements at the back face of the plate.

A simultaneous in- and out-of-plane displacement measurement method.

A method is presented that allows real-time three-dimensional displacement maps to be obtained for deformable objects using a single color camera and a color fringe projector. The acquired images have speckle and fringe information embedded in them, which are separated using the R, G, and B color signals from a color CCD camera to permit the independent use of a two-dimensional digital image correlation to obtain the x- and y-direction displacements and fringe projection to obtain the displacement in the z direction.

Robust approach to regularize an isochromatic fringe map.

The computation of a continuous map of isochromatic fringe order from an isochromatic phase map or relative retardation based on a photoelastic fringe pattern is a difficult task, particularly when the direction of the principal stress is ambiguous. This happens in most experiments and introduces abrupt changes in the slope of the computed relative retardation map. We present a novel regularized phase-tracking method that at each pixel chooses the unambiguous relative retardation value.