Extracting fracture parameters using local collocation of full-field displacement data

Conclusions

Least-squares analysis of optically measured displacement data for extracting fracture parameters in homogeneous and bimaterial beams is discussed. The u₂-displacements measured using moiré interferometry are analyzed and fracture parameters are extracted. The feasibility of using K-dominant expressions along with the higher order terms specific to loading configuration is successfully demonstrated for the case of three-point-bending. Elasticity solution of an un-cracked beam when used as higher order terms along with K-dominant terms provide accurate measurement of stress intensity factors. The method offers an alternative for using asymptotic fields for fringe analysis wherein the number of terms needed for an accurate fracture parameter extraction is generally unknown and involves a trial and error process.