| The broad objective of this research is to develop a computer-vision-based, full-field measurement technique for characterizing time dependent fracture at elevated temperatures and apply this technique to investigate creep fracture behavior of two super-alloys. In this research, the newly developed high temperature digital image correlation technique was applied to obtain crack tip displacement and strain fields associated with stationary and growing cracks. It is believed that this is perhaps the first study that presents quantitative comparisons at elevated temperature between experimentally measured near-crack-tip deformations fields and theoretical solutions.;The first part of the dissertation describes the development of the high temperature digital image correlation technique. A series of verification tests is conducted at a temperature of 650;The second part of this dissertation deals with two experimental studies of time-dependent fracture at elevated temperature using digital image correlation. The results of the first experiment show that the stress intensity factor, K;In addition, finite element analysis is performed using the ABAQUS program for both linear elastic and steady-state creep cases. Experimental and finite element analysis results are compared in both radial and angular variations, as well as line integration form. |
