US4959548A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Neutron apparatus for measuring strain in composites
Assignee: United States Department of Energy
•
Filing: 1989-05-02
•
Granted: 1990-09-25
•
Expires: 2009-05-02
Abstract
Abstract A method and apparatus for orienting a pulsed neutron source and a multi-angle diffractometer toward a sample of a ceramic-matrix or metal-matrix composite so that the measurement of internal strain (from which stress is calculated) is reduced to uncomplicated time-of-flight measurements.
Inventors
- 👤 David S. Kupperman
- 👤 Saurindranath Majumdar
- 👤 John F. Faber, Jr.
- 👤 J. P. Singh
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 05:58
CPC Classifications
G; G01; G01N; G01N23/00; G01N23/20; G01N23/207; G01N23/2073; G01L; G01L1/00; G01L1/25
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
70 words
A method for real-time simultaneous measurement of strain in the constituents of a composite comprising: directing a polychromatic beam of neutrons from a pulsed source toward a sample, orienting a multi-angle diffractometer so that two opposite detectors are on a line perpendicular to said neutron beam, measuring, using Bragg's law, the strain on a vector bisecting the angle between said neutron beam and said line perpendicular to said neutron beam.
Claim 2
Independent Claim
70 words
A method for real-time simultaneous measurement of strain in the constituents of a composite comprising: directing a polychromatic beam of neutrons from a pulsed source toward a sample, orienting a multi-angle diffractometer so that two opposite detectors are on a line perpendicular to said neutron beam, measuring, using Bragg's law, the strain on a vector bisecting the angle between said neutron beam and said line perpendicular to said neutron beam.
Claim 3
Dependent Claim
14 words
The method of claim 1 wherein said sample is a ceramic-matrix or metal-matrix composite.
Claim 4
Dependent Claim
44 words
The method of claim 2 wherein said sample is oriented so that a line parallel to the longitudinal direction of the fiber embedded in said ceramic-matrix or metal-matrix composite bisects the angle between said neutron beam and said line perpendicular to said neutron beam.
Claim 5
Dependent Claim
38 words
The method of claim 3 including, calculating, using Bragg's law, the strain parallel to the longitudinal direction of the fibers and the strain perpendicular to the longitudinal direction of the fibers embedded in said ceramic-matrix or metal-matrix composite.
Claim 6
Dependent Claim
33 words
The method of claim 4 including collimating said neutron beam and orienting said neutron beam toward a small volume within said ceramic-matrix or metal-matrix composite and measuring the strain within said small volume.
Claim 7
Dependent Claim
33 words
The method of claim 5 including orienting said neutron beam toward a multiplicity of small volumes within said ceramic-matrix or metal-matrix composite and averaging the strain measured within said multiplicity of small volumes.
Claim 8
Dependent Claim
37 words
The method of claim 4 including calculating the residual stress in a ceramic-matrix or metal-matrix composite by comparing the time-of-flight of neutrons in an unstressed sample to the time of flight of neutrons in a stressed sample.
Claim 9
Dependent Claim
31 words
The method of claim 7 including validating models for determination of residual stress by comparing residual stress as projected by said models to the results of said calculations of residual stress.
Claim 10
Dependent Claim
18 words
The method of claim 2 wherein said sample is a composite of A1 2 O 3 and SiC.
Claim 11
Dependent Claim
38 words
The method of claim 9 wherein said sample is oriented so that a line parallel to the {111} plane of the SiC whisker bisects the angle between said neutron beam and said line perpendicular to said neutron beam.
Claim 12
Independent Claim
71 words
A method of determining the strain at the fiber-matrix interface in a ceramic-matrix or metal-matrix composite comprising: determining the lattice spacing d over a volume of a strain-free powdered sample of a ceramic-matrix or metal-matrix composite, determining the lattice spacing d 0 associated with a particular lattice plane in a stressed sample of said composite, calculating the strain associated with said lattice plane using the formula e=(d-d 0 )/d 0 .
Claim 13
Independent Claim
71 words
A method of determining the strain at the fiber-matrix interface in a ceramic-matrix or metal-matrix composite comprising: determining the lattice spacing d over a volume of a strain-free powdered sample of a ceramic-matrix or metal-matrix composite, determining the lattice spacing d 0 associated with a particular lattice plane in a stressed sample of said composite, calculating the strain associated with said lattice plane using the formula e=(d-d 0 )/d 0 .
Claim 14
Independent Claim
52 words
An apparatus for the real-time measurement of strain comprising: a pulsed neutron source emitting a neutron beam, a multi-angle diffractometer oriented so that two opposite detectors are on a line perpendicular to said neutron beam, means for determining the time of flight of said diffracted neutrons from a sample to said detectors.
Claim 15
Independent Claim
52 words
An apparatus for the real-time measurement of strain comprising: a pulsed neutron source emitting a neutron beam, a multi-angle diffractometer oriented so that two opposite detectors are on a line perpendicular to said neutron beam, means for determining the time of flight of said diffracted neutrons from a sample to said detectors.
References Cited (Backward Citations)
US3934138A
Cited
SU1293594A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-09-24 | 1994-03-26 | 1994-09-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-09-24 | 1998-03-26 | 1998-09-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-09-24 | 2002-03-26 | 2002-09-25 | $7700.00 | Window Closed / Lapsed |