A Dynamic Tear (DT) test machine was designed and constructed. With the machine, a series of 50 DT tests was conducted with CSA G40.8-1971, grades A and B steels over a wide range of temperature to study their fracture behavior. From 5/8 in. DT test results, the Nil-Ductility Transition (NDT) temperatures of the steels were determined as -10°C and -30°C for the grades A and B steels, respectively. The critical stress intensity
factors, KIC, of the steels were inferred to be 415 and 260 Ksi √in. respectively from the 5/8 in. DT tests.
Temperature Transition Charpy V-Notch Impact (Cv) tests were conducted for the steels as ancillary tests, and Fracture Extension Resistance (R-curve) tests were conducted for the grade A steel. The Cv test results were compared with the DT test results.
From the DT test results, a Fracture Analysis Diagram (FAD) and a Ratio Analysis Diagram (RAD) were constructed and, subsequently, criteria for material selection and fracture-safe engineering design were inferred.