Volume 7, Issue 6 (November 1979)
Determination of the Fracture-Energy Criterion JIc of Two Steels by Static and Dynamic Testing
The fracture energy criterion JIc was determined on two carbon-manganese steels, SA-516-70 and SA-105-B, from a single specimen. A graphic method is proposed for verifying the validity of measured values of JIc. Static JIc and dynamic JIcD experiments on precracked Charpy V-notch specimens at ambient temperature enabled the observation of the effect of loading rate on the value of JIc. For these two steels, the effect of side grooves was detected only in dynamic testing. For SA-516-70 steel, JIcD > JIc, while JIcD > JIc for SA-105-B steel, because of transition temperature fracture behavior. For SA-516-70, static testing was performed on three-point bend specimens of different dimensions to determine the effect of geometrical parameters on the value of JIc. A ligament 1-cm long is the lower limit for the determination of JIc.