US4080836A
Expired / Lapsed
US
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Method of measuring stress in a material
Assignee: Boeing North American Inc
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Filing: 1977-03-07
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Granted: 1978-03-28
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Expires: 1997-03-07
Abstract
Abstract Stress in a material is measured using electromagnetically generated, transverse elastic waves. A correlation is known to exist between the difference in velocity of orthogonally polarized transverse waves in the type material being measured and stress in the material. An electromagnetic transducer is used to generate orthogonally polarized waves traveling through the part at different velocities as a result of anisotropic stress in the part. The difference in velocity between the polarized waves is measured and compared to the correlation to obtain the stress existing in the part.
Inventors
- 👤 Robert B. Thompson
- 👤 George A. Alers
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 22:37
CPC Classifications
G; G01; G01N; G01N29/00; G01N29/22; G01N29/24; G01N29/2412; G01N29/04; G01N29/07; G01N2291/00; G01N2291/04; G01N2291/042; G01N2291/0421; G01N2291/0422
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
99 words
A method of measuring stress in a material comprising the steps of: a) obtaining a correlation between the difference in velocity of orthogonally polarized transverse waves in the material and stress in the material; b) simultaneously applying a plurality of differently oriented driving forces to the surface of the material from a single electromagnetic transducer; c) allowing said driving forces to radiate orthogonally polarized transverse waves through the material; d) determining the difference in velocity between said orthogonally polarized transverse waves; and e) comparing said difference in velocity to said correlation, whereby stress can be measured in said material.
Claim 2
Independent Claim
99 words
A method of measuring stress in a material comprising the steps of: a) obtaining a correlation between the difference in velocity of orthogonally polarized transverse waves in the material and stress in the material; b) simultaneously applying a plurality of differently oriented driving forces to the surface of the material from a single electromagnetic transducer; c) allowing said driving forces to radiate orthogonally polarized transverse waves through the material; d) determining the difference in velocity between said orthogonally polarized transverse waves; and e) comparing said difference in velocity to said correlation, whereby stress can be measured in said material.
Claim 3
Dependent Claim
25 words
The method as claimed in claim 1 wherein said step of applying driving forces comprises applying said forces in a plurality of radially oriented directions.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-03-27 | 1981-09-26 | 1982-03-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-03-27 | 1985-09-26 | 1986-03-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-03-27 | 1989-09-26 | 1990-03-28 | $7700.00 | Window Closed / Lapsed |