Probabilistic Model for Brittle Fracture and Statistical Characteristic of Absorbed Energy in Charpy Impact Test

This paper discusses a theoretical approach to evaluating the statistical characteristics of Charpy absorbed energy to brittle fracture at low temperature. First, the probability distribution of fracture toughness for V-notch specimen was derived by combining a local fracture criterion and Weibull distribution. Second, a probabilistic model for the Charpy absorbed energy was derived by relating the fracture toughness and the Charpy absorbed energy based on the concept of Griffith-Orowan-Irwin. The Charpy absorbed energy was related to the material strength and the material constant, obeying the two-parameter Weibull distribution with a shape parameter of 2. Third, the Weibull analysis of the Charpy absorbed energy for V-notch specimen of high strength steel at lower temperature than Ductile-Brittle Transition Temperature (DBTT) and the statistical characteristics obtained from the model were compared. As a result, the proposed model was supported the statistical characteristics of the Charpy absorbed energy at a temperature sufficiently lower than DBTT.