ABSTRACT
The PMMA plate is used to simulate the brittle material and en echelon cracks are prefabricated on the plates. The computer program dealing with the interaction among multi inclusions has been written based on the equivalent inclusion method modified from Moschovidis’ procedure. The stress field of En-echelon Cracks has been computed by the program and compared well with those observed by real-time holographic interferometry. The dark shadow areas observed in the real time hologram experiment are the phenomena of caustic in Geometry Optics. The stress intensity factor can be calculated by measuring the size of the corresponding length of the shadow spot according to Fracture Mechanics theory.
