Plastic deformation around the tip of a stopped brittle crack in the Robertson test with a temperature gradient

✍ Scribed by K. Ishikawa; K. Tsuya

• Publisher: Elsevier Science
• Year: 1974
• Tongue: English
• Weight: 606 KB
• Volume: 6
• Category: Article
• ISSN: 0013-7944
• DOI: 10.1016/0013-7944(74)90066-6

✦ Synopsis

Abstrae-Robertson tests with imposed temperature gradients were carried out to investigate crack stopping in structural steels. Mkcroscopic fracture toughness in plane strain and plane stress conditions were evaluated using linear elastic fracture mechanics to study the effect of various testing conditions. Both values were expected to be almost equal. On the other hand, microscopic fracture toughness was then deduced from the concept of maximum plastic deformation ahead of the stopped crack tip. The macroscopic and the microscopic fracture toughness agreed well.

The fracture toughness for arrest is shown to depend on extent of plastic deformation at some distance ahead of the stopped crack tip. In consequence, the shear lip on the fracture surface is likely to play only a secondary role in causing arrest.