Preface to the Special Issue on the Sandia Fracture Challenge

Abstract

Despite many advances in fracture mechanics and computational analysis methods over the past several decades, there are still certain classes of problems in failure of structural materials that are difficult to predict. One such class of problems can be generally categorized as ductile tearing of metals and alloys. Ductile tearing has been an enduring challenge in the metal forming industry, where certain rubrics like forming limit diagrams provide utilitarian solutions, but are limited in applicability. The 2012 Sandia Fracture Challenge was pursued as a means to evaluate the ‘state-ofthe-art’ in prediction of ductile tearing. As a precursor to the Sandia Fracture Challenge, a series of internal blindprediction assessmentswere performed at Sandia National Laboratories. These efforts, some of which were documented in a 2011 report [Report number SAND2011-6801], demonstrated the difficulty in accurate computational prediction of ductile tearing failures. Several deficiencies were highlighted: (a) the need for an accurate assessment of finite deformation as a prerequisite for accurate failure modeling, (b) the limitations of a tensile test as the sole