Statistical Aspects of Constraint with Emphasis on Testing and Analysis of Laboratory Specimens in the Transition Region

Abstract

The effect of specimen thickness, side grooving, large-scale yielding of the ligament, and ductile tearing upon the probability of cleavage fracture initiation is examined within the framework of a general statistical model for cleavage fracture initiation. First, a derivation of the statistical model is presented, and then the model is used to explain the effects of different factors affecting the cleavage fracture probability. As a result, a specimen size requirement for elastic-plastic cleavage fracture toughness testing with bend-type specimens is obtained. Additionally, a simple correction function to validate invalid test results with insufficient ligament size and prior ductile tearing is presented.