Fracture toughness determination using spiral-grooved cylindrical specimen and pure torsional loading
US6588283B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 25, 2001 |
| Grant date | Jul 8, 2003 |
| Priority date | — |
| Expiry date | Jun 25, 2021 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2203/027
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method for determining fracture toughness KIC of materials ranging from metallic alloys, brittle ceramics and their composites, and weldments. A cylindrical specimen having a helical V-groove with a 45° pitch is subjected to pure torsion. This loading configuration creates a uniform tensile-stress crack-opening mode, and a transverse plane-strain state along the helical groove. The full length of the spiral groove is equivalent to the thickness of a conventional compact-type specimen. KIC values are determined from the fracture torque and crack length measured from the test specimen using a 3-D finite element program (TOR3D-KIC) developed for the purpose. In addition, a mixed mode (combined tensile and shear stress mode) fracture toughness value can be determined by varying the pitch of the helical groove. Since the key information needed for determining the KIC value is condensed in the vicinity of the crack tip, the specimen can be significantly miniaturized without the loss of generality.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.