General Yielding of Charpy V-Notch and Precracked Charpy Specimens

By applying a slip-line fields solution for general yielding, which includes the tup indenter for Charpy V-notch and precracked Charpy tests, estimates of high loading-rate yield stress values can be obtained. These values of yield stress are of particular interest for loading-rate sensitive materials such as low strength steels. Normal tensile tests are not performed at strain-rates indicative of impact tests; dynamic fracture toughness tests require the knowledge of dynamic yield stresses for the determination of validity limits for the fracture toughness measurements. This paper reviews the calculation of yield stresses from static and dynamic three-point bend tests and presents data for a nuclear pressure vessel steel which shows good agreement with high rate and conventional tensile test data.