Review of fracture toughness test methods for ductile materials in low-constraint conditions

摘要

Fracture toughness is an important material property to describe the ability of a material containing a crack to resist fracture, and often characterized by the fracture parameters of J-integral or crack-tip opening displacement (CTOD) for ductile cracks. ASTM, BSI and ISO have developed their own standard test methods for measurement of initiation toughness and resistance curves in terms off and CTOD using bending dominant specimens. Such bending specimens are typically designed with deep cracks to maintain high constraint conditions at the crack tip so as to determine conservative fracture toughness or resistance curve for the test material.