Abstract
An alternative fracture toughness test, J Evaluation Tensile Test (JETT) have been conducted. A thickness of EDM heat affected zone generated around a notch tip was measured in this research. In low carbon steel, the thickness was 50μm for the specimen with ligament diameter b=3mm. Comparing the thickness with numerically obtained high stress tri-axiality region where a fracture is likely to initiate is needed to substitute a EDM notch for a fatigue crack. The method to selected an appropriate JETT specimen size was proposed in this research.
