The term fracture toughness usually refers to the linear elastic fracture resistance parameter KIC. In the case of structural steels. The estimation of KIC is limited to the lower shelf of toughness or requires extremely large specimens. This specimen size requirement has been one major obstacle for applying fracture mechanics in structural integrity assessment outside aviation, nuclear and off-shore industries. During the last decade, a statistical data treatment methodology, based on a micro-mechanistic cleavage fracture model, combined with elastic plastic finite element analysis has enabled the fracture toughness to be characterised with small specimens in Ihe ductile to brittle transition region. The development has led to a new testing standard for fracture toughness testing of ferritic steels in the transition range (ASTM E1921-97). Here, the premises for the methodology are described and its validity range is discussed. Presently the methodology has been validated for as small as 10 x 10 mm² bend specimens, but the use of even smaller specimens is under investigation.
|Number of pages||13|
|Journal||International Journal of Materials and Product Technology|
|Publication status||Published - 1999|
|MoE publication type||A1 Journal article-refereed|