A TECHNIQUE FOR EXPERIMENTAL EVALUATION OF MIXED-MODE STRESS INTENSITY FACTORS

High sensitivity moire interferometry was used to obtain whole-field o rthogonal components of displacement in the vicinity of cracks in cent re-cracked plates of aluminium 6082. The plates had been prepared in s uch a way as to enable the application of load at angles of 75-degrees and 60-degrees to the planes of the fatigue pre-cracks. The form of t he moire fringe data enables convenient separation of the components o f stress intensity factor K(I) and K(II). The results are compared wit h analytical predictions. The method is, in principle, suitable for us e with specimens of arbitrary geometry and loading.