Eddy current sensor with concentric segments
US7994781B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 3, 2009 |
| Grant date | Aug 9, 2011 |
| Priority date | — |
| Expiry date | Aug 3, 2029 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB24B21/06
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
Reference standards or articles having prescribed levels of damage are fabricated by monitoring an electrical property of the article material, mechanically loading the article, and removing the load when a change in electrical properties indicates a prescribed level of damage. The electrical property is measured with an electromagnetic sensor, such as a flexible eddy current sensor, attached to a material surface, which may be between layers of the article material. The damage may be in the form of a fatigue crack or a change in the mechanical stress underneath the sensor. The shape of the article material may be adjusted to concentrate the stress so that the damage initiates under the sensor. Examples adjustments to the article shape include the use of dogbone geometries with thin center sections, reinforcement ribs on the edges of the article, and radius cut-outs in the vicinity of the thin section. A test circuit includes sensing elements between concentric circular segments of the primary winding and located every other half wavelength of the primary winding.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.