DUCTILE FRACTURE ASSESSMENT OF PLATES UNDER BIAXIAL LOADING

There is currently little detailed advice on biaxial and triaxial effects on fracture in fitness-for-service codes and engineering assessment procedures. There has been historical and recent research into such effects using numerical, finite element and experimental investigations into biaxial effects on fracture toughness and J-integral estimation. However, these studies cover only limited ranges of loadings with, for example, few investigations into loading regimes where the biaxial ratio exceeds unity, i.e. where the loading in the direction of a crack exceeds the crack opening force. This paper first briefly summarises a literature review focussing on the experimental information available on the effects of biaxial loading on ductile fracture. It transpires that although there have been a number of numerical and experimental investigations of biaxial fracture a systematic examination of the effects of biaxial loading is missing in terms of the effect on the crack driving force. Therefore, the paper develops advice for assessment of simple plate geometries under a wide range of biaxial loading conditions to provide advice and recommendations for future inclusion in fitness-for service codes.