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US4744252A
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Triple-material stress-strain resistivity gage
Assignee: United States Department of Energy
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Filing: 1987-05-19
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Granted: 1988-05-17
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Expires: 2007-05-19
Abstract
Abstract A triple material piezoresistive gage provides multi-component elastic stress or measurements. Thin foils of three piezoresistive materials, e.g. ytterbium, manganin, and constantan, are configured in a nested serpentine rectilinear grid or other grid arrangement and embedded in a medium, preferably normal to the direction of shock wave propagation. The output of the gage is a resistivity change history for each material of the gage. Each resistivity change is independent of the others so that three diagonal components of the elastic stress or strain tensor can be calculated from the resistivity measurements.
Inventors
- 👤 Ray B. Stout
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 17:14
CPC Classifications
G; G01; G01B; G01B7/00; G01B7/16; G01B7/18
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
22 words
A stress-strain gage comprising three thin foils of different stress-strain sensitive resistivity materials to provide three independent response measurements of resistance changes.
Claim 2
Dependent Claim
22 words
A stress-strain gage comprising three thin foils of different stress-strain sensitive resistivity materials to provide three independent response measurements of resistance changes.
Claim 3
Dependent Claim
16 words
The gage of claim 1 wherein the three foils are made from ytterbium, manganin, and constantan.
Claim 4
Dependent Claim
17 words
The gage of claim 2 wherein the three foils are configured in a nested serpentine rectilinear grid.
Claim 5
Dependent Claim
23 words
The gage of claim 2 further including means operatively connected to the foils for separately and simultaneously measuring the resistance of each foil.
Claim 6
Dependent Claim
17 words
The gage of claim 1 wherein the three foils are configured in a nested serpentine rectilinear grid.
Claim 7
Dependent Claim
23 words
The gage of claim 5 further including means operatively connected to the foils for separately and simultaneously measuring the resistance of each foil.
Claim 8
Dependent Claim
23 words
The gage of claim 1 further including means operatively connected to the foils for separately and simultaneously measuring the resistance of each foil.
Claim 9
Dependent Claim
15 words
The gage of claim 1 wherein the three foils are mounted on a backing material.
Claim 10
Dependent Claim
23 words
The gage of claim 1 wherein the three foils are embedded in a body or structure wherein a multi-component stress-strain fie1d is produced.
Claim 11
Dependent Claim
22 words
The gage of claim 9 wherein the three foils are oriented normal to a shock wave propagating through the body or structure.
Claim 12
Dependent Claim
70 words
A stress-strain measurement apparatus for determining multi-components of a stress-strain tensor in a multi-component stress-strain field, comprising: a piezoresistive element comprising a plurality of thin foils of different stress-strain sensitive resistivity materials; resistance measurement means operatively connected to the piezoresistive element to provide independent response measurements of resistance changes; conversion means associated with the resistance measurement means for converting the measurements of resistance changes to components of the stress-strain tensor.
Claim 13
Dependent Claim
70 words
A stress-strain measurement apparatus for determining multi-components of a stress-strain tensor in a multi-component stress-strain field, comprising: a piezoresistive element comprising a plurality of thin foils of different stress-strain sensitive resistivity materials; resistance measurement means operatively connected to the piezoresistive element to provide independent response measurements of resistance changes; conversion means associated with the resistance measurement means for converting the measurements of resistance changes to components of the stress-strain tensor.
Claim 14
Dependent Claim
14 words
The apparatus of claim 11 comprising three foils made from ytterbium, manganin, and constantan.
Claim 15
Dependent Claim
16 words
The apparatus of claim 11 wherein the foils are configured in a nested serpentine rectilinear grid.
Claim 16
Independent Claim
71 words
A method of measuring multi-component stress or strain tensor in a multi-component stress or strain field in a body or structure, comprising: embedding a piezoresistive element comprising a plurality of thin foils of different stress-strain sensitive resistivity materials in the body or structure; making simultaneous independent response measurements of resistance changes of the thin foils of the piezoresistive element; converting the measurements of resistance changes to components of the stress-strain tensor.
Claim 17
Independent Claim
71 words
A method of measuring multi-component stress or strain tensor in a multi-component stress or strain field in a body or structure, comprising: embedding a piezoresistive element comprising a plurality of thin foils of different stress-strain sensitive resistivity materials in the body or structure; making simultaneous independent response measurements of resistance changes of the thin foils of the piezoresistive element; converting the measurements of resistance changes to components of the stress-strain tensor.
Claim 18
Dependent Claim
19 words
The method of claim 14 further comprising forming the piezoresistive element of three foils of ytterbium, manganin, and constantan.
Claim 19
Dependent Claim
23 words
The method of claim 14 further including orienting the piezoresistive element substantially normal to a shock wave propagating through the body or structure.
Claim 20
Dependent Claim
16 words
The method of claim 14 further including forming the foils into a nested serpentine rectilinear grid.
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) | 1991-05-17 | 1991-11-16 | 1992-05-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-05-17 | 1995-11-16 | 1996-05-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-05-17 | 1999-11-16 | 2000-05-17 | $7700.00 | Window Closed / Lapsed |