Evaluating stress intensity factor of polycarbonate using digital image correlation

The application of the digital image correlation (DIC) method to determine the stress intensity factor (SIF) for cracks in Polycarbonate is proposed in this paper. Standard compact tension specimen was tested under tensile loading and the full-field displacement fields of the test sample were recorded using DIC. According to linear elastic fracture mechanics, the SIF associated with unavoidable rigid-body displacement translation and rotation were calculated simultaneously from the experimental data by fitting the theoretical displacement field using the method of least-squares. Selection of displacement and convergence values is discussed. The effectiveness and accuracy of the proposed technique is verified by comparison with theoretical results, which reveals that the DIC is a practical and effective tool for full-field deformation and SIF measurement.