Off-Axis 2d Displacement Fields Evaluation by Digital Image Correlation Using Markers

Digital image correlation is a mathematical technique which can be used successfully for evaluation displacements and deformations of large engineering components.Compared to traditional contact measurements, digital image correlation allows full-field deformation information to be obtained by non-contact procedure.Herein, we propose a method to improve the accuracy in evaluation of two dimensional displacement fields by introducing markers, which are used during the following digital image correlation analysis.The effectiveness of the proposed method is illustrated in processing of displacement fields on the surface of a wooden wall, subjected to cyclic loading.The results are in good agreement (less than 1%) with the data obtained by linear voltage differential transformer sensors.Experiments show that the use of markers is a perspective way to improve the accuracy of a digital image correlation method, and to improve its applicability in structural monitoring.