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ABSTRACT. IN GENERAL, THE TECHNIQUES USED FOR STUDYING SHORT CRACK GROWING ARE MODIFICATIONS OF THE TECHNIQUES USED IN LONG CRACKS. THIS WORK REVIEWS THE EXPERIMENTAL TECHNIQUES USED IN SHORT CRACK STUDY, ABOUT THE MEASURE FORMS OF INITIATION, PROPAGATION, THRESHOLD AND CLOSURE. IT DOES NOT EXIST A TYPE OF SPECIMEN UNIVERSALLY ACCEPTED FOR STUDYING SHORT CRACKS, NEITHER PROPAGATION MODEL WHICH EFFICIENTLY COVER THE DIFFERENT PROBLEMS OF THESE, SUCH AS ITS MAJOR PROPAGATION VELOCITY COMPARED WITH ONE LONG CRACK SUBJECTED TO THE SAME NOMINAL CRACKING FORCE. PLASTIC FATIGUE STANDARD SPECIMENS OF VARIABLE SECTION FOR LOW NUMBER OF CYCLES WERE USED, OF AISI 316L STEEL, SUBJECTED TO PLASTIC DEFORMATION AMPLITUDES, EQUAL TO 0,0040, 0,0087, 0,0135 AND 0,0183. THE TESTS WERE MADE UNDER DIAMETRAL DEFORMATION CONTROL. IT WAS OBSERVED A DESACCELERATION OF THE SHORT CRACKS, DURING AN IMPORTANT PERIOD OF ITS PROPAGATION IN STAGE I. BESIDES, THE FOLLOWING PROPAGATION STAGE WAS TO PASS TO MODE I GROWING. SINCE MICROHARDNESS MEASUREMENTS AT CRACK TIP, THE PLASTIC ZONE COULD BE CALCULATED AND ONE SOFTENING ZONE WAS APPRECIATED AT THE CRACK TIP FRONT, MEANING THE POTENTIALITY OF THIS METHOD.
KEY-WORDS: FRACTURE MECHANICS, FATIGUE, SHORT CRACKS
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