Patent US4567774A successfully refreshed from Google Patents.
US4567774A
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Determining mechanical behavior of solid materials using miniature specimens
Assignee: Battelle Development Corp
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Filing: 1983-04-28
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Granted: 1986-02-04
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Expires: 2003-04-28
Abstract
Abstract A Miniaturized Bend Test (MBT) capable of extracting and determining mechanical behavior information from specimens only so large as to have at least a volume or smallest dimension sufficient to satisfy continuum behavior in all directions. The mechanical behavior of the material is determined from the measurements taken during the bending of the specimen and is processed according to the principles of linear or nonlinear material mechanics or both. In a preferred embodiment the determination is carried out by a code which is constructed according to the finite element method, and the specimen used for the determinations is a miniature disk simply supported for central loading at the axis on the center of the disk.
Inventors
- 👤 Michael P. Manahan
- 👤 Ali S. Argon
- 👤 Otto K. Harling
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 19:45
CPC Classifications
G; G01; G01N; G01N3/00; G01N3/20; F; F02; F02B; F02B75/00; F02B75/02; F02B2075/022; F02B2075/027; G01N2203/00; G01N2203/0014; G01N2203/0016; G01N2203/0019; G01N2203/0023; G01N2203/02; G01N2203/026; G01N2203/0286; G01N2203/04; G01N2203/0482; G01N2203/0494
Claims Analysis
Total Claims: 65
Claim 1
Independent Claim
113 words
A process of determining mechanical behavior of solid material, comprising: a. providing a specimen of the material having at least a volume and smallest dimension sufficient to satisfy continuum behavior in all directions, and with the volume not more than 10 7 times said sufficient volume; b. deforming the specimen by applying a load on the specimen; c. measuring at least one key variable in step b; and d. determining the tensile behavior of the material from the measurements taken according to the principles of the finite element method, and/or determining other mechanical behavior of the material from the measurements taken according to the principles of linear or nonlinear material mechanics or both.
Claim 2
Dependent Claim
113 words
A process of determining mechanical behavior of solid material, comprising: a. providing a specimen of the material having at least a volume and smallest dimension sufficient to satisfy continuum behavior in all directions, and with the volume not more than 10 7 times said sufficient volume; b. deforming the specimen by applying a load on the specimen; c. measuring at least one key variable in step b; and d. determining the tensile behavior of the material from the measurements taken according to the principles of the finite element method, and/or determining other mechanical behavior of the material from the measurements taken according to the principles of linear or nonlinear material mechanics or both.
Claim 3
Dependent Claim
27 words
A process according to claim 1 wherein either the applied load or the displacement of the specimen (or both) is (are) measured as a function of time.
Claim 4
Dependent Claim
23 words
A process according to claim 1 wherein the specimen is a disk and the load is applied on a face of the disk.
Claim 5
Dependent Claim
17 words
A process according to claim 3 wherein the specimen is supported on a face of the disk.
Claim 6
Dependent Claim
37 words
A process according to claim 4 wherein the disk is supported on a face near the edge and the load is applied by a rounded punch on the opposite face substantially at the center of the disk.
Claim 7
Dependent Claim
15 words
A process according to claim 5 wherein the load is applied either once or repeatedly.
Claim 8
Dependent Claim
38 words
A process according to claim 5 wherein the material is a post-irradiated stainless steel and the process is carried out in an inert atmosphere at a temperature of about 0° K. to the melting temperature of the material.
Claim 9
Dependent Claim
31 words
A process according to claim 4 wherein the load is applied alternately and oppositely between a rounded punch on each face of the disk, substantially at the center of the disk.
Claim 10
Dependent Claim
13 words
A process according to claim 8 wherein the disk is in unconfined support.
Claim 11
Dependent Claim
19 words
A process according to claim 8 wherein the disk is supported and clamped on the faces near the edges.
Claim 12
Dependent Claim
37 words
A process according to claim 4 wherein the disk is in unconfined support on one face near the edge and the load is applied by a rounded annular punch with the annulus substantially coaxial with the disk.
Claim 13
Dependent Claim
26 words
A process according to claim 4 wherein the load is applied alternately and oppositely between rounded annular punches substantially coaxial with the disk on each face.
Claim 14
Dependent Claim
13 words
A process according to claim 12 wherein the disk is in unconfined support.
Claim 15
Dependent Claim
19 words
A process according to claim 12 wherein the disk is supported and clamped at the faces near the edges.
Claim 16
Dependent Claim
38 words
A process according to claim 4 wherein the disk is clamped and sealed on opposite faces near the edge and the load is applied by fluid pressure uniformly distributed across a face of the disk on one side.
Claim 17
Dependent Claim
42 words
A process according to claim 4 wherein the disk is sealed near the edge on one face, and the load is applied by fluid pressure uniformly distributed across the exposed face of the disk on the face opposite to the sealed face.
Claim 18
Dependent Claim
36 words
A process according to claim 4 wherein the disk is clamped and sealed on opposite faces near the edge and the load is applied by fluid pressure uniformly distributed alternately on opposite faces of the disk.
Claim 19
Dependent Claim
34 words
A process according to claim 4 wherein the disk is sealed on opposite faces near the edge and the load is applied by fluid pressure uniformly distributed alternately on opposite sides of the disk.
Claim 20
Dependent Claim
23 words
A process according to claim 1 wherein the specimen is a beam and the load is applied on a face of the beam.
Claim 21
Dependent Claim
17 words
A process according to claim 19 wherein the specimen is supported on a face of the beam.
Claim 22
Dependent Claim
45 words
A process according to claim 20 wherein the specimen is clamped at one side and the load is applied on one or both faces at a position spaced and the clamped side either once or repeatedly, so that the specimen reacts as a cantilever beam.
Claim 23
Dependent Claim
20 words
A process according to claim 21 wherein the load is applied by a rounded punch or a substantially cylindrical surface.
Claim 24
Dependent Claim
40 words
A process according to claim 20 wherein the specimen is clamped at one side and the load is applied alternately on each face a position spaced from the clamped side repeatedly, so that the specimen reacts as a cantilever beam.
Claim 25
Dependent Claim
20 words
A process according to claim 23 wherein the load is applied by a rounded punch or a substantially cylindrical surface.
Claim 26
Dependent Claim
40 words
A process according to claim 20 wherein the beam is supported on a face near opposite edges and the load is applied on the opposite face, substantially at the center, by either a rounded punch or a substantially cylindrical surface.
Claim 27
Dependent Claim
15 words
A process according to claim 25 wherein the load is applied either once or repeatedly.
Claim 28
Dependent Claim
36 words
A process according to claim 20 wherein the load is applied alternately and oppositely between a rounded punch or a substantially cylindrical surface on each face of the beam, substantially at the center of the beam.
Claim 29
Dependent Claim
13 words
A process according to claim 27 wherein the beam is in unconfined support.
Claim 30
Dependent Claim
19 words
A process according to claim 27 wherein the beam is supported and clamped on the faces near opposite edges.
Claim 31
Dependent Claim
39 words
A process according to claim 20 wherein the beam is placed in unconfined support on one face near opposite edges and the load is applied by two substantially cylindrical surfaces, at equal distances from the center of the beam.
Claim 32
Dependent Claim
31 words
A process according to claim 20 wherein the load is applied alternately and oppositely between substantially cylindrical surfaces, two on each face, at equal distances from the center of the beam.
Claim 33
Dependent Claim
13 words
A process according to claim 31 wherein the beam is in unconfined support.
Claim 34
Dependent Claim
19 words
A process according to claim 31 wherein the beam is supported and clamped at the faces near the edges.
Claim 35
Dependent Claim
14 words
A process according to claim 1 wherein the specimens are of a cruciform shape.
Claim 36
Dependent Claim
33 words
A process according to claim 1 wherein the determining step d for other mechanical behavior is carried out according to the processes of continuum material mechanics and according to the finite element method.
Claim 37
Dependent Claim
23 words
A process according to claim 35 wherein boundary condition modelling for the finite element method is carried out using shadow node mapping theory.
Claim 38
Dependent Claim
13 words
A process according to claim 1 wherein the specimen comprises an irradiated material.
Claim 39
Dependent Claim
24 words
A process according to claim 1 wherein the specimen comprises a plurality of layers of material having different mechanical behavior response in each layer.
Claim 40
Dependent Claim
32 words
A process according to claim 38 wherein the specimen comprises an ion-irradiated specimen with a radiation damaged layer of unknown mechanical behavior and a layer of unirradiated material of known mechanical behavior.
Claim 41
Dependent Claim
16 words
A process according to claim 1 wherein a plurality of specimens are tested together and simultaneously.
Claim 42
Dependent Claim
32 words
A process according to claim 1 wherein the specimen comprises a material that behaves substantially as isotropic, a material that behaves substantially as anisotropic, or a material that behaves substantially as orthotropic.
Claim 43
Dependent Claim
23 words
A process according to claim 1 wherein steps b and c are carried out in a nuclear reactor or other appropriate irradiation facility.
Claim 44
Dependent Claim
30 words
A process according to claim 1 wherein the process is carried out in a controlled environment at a temperature of about 0° K. to the melting temperature of the material.
Claim 45
Dependent Claim
15 words
A process according to claim 1 wherein the specimen is trepanned from an inservice material.
Claim 46
Dependent Claim
19 words
A process according to claim 1 wherein the smallest dimension is substantially the continuum mechanics limit of the material.
Claim 47
Dependent Claim
84 words
A process according to claim 1 wherein the specimen providing step a comprises: a'. providing a strain gage on the surface of a strained inservice material; b'. trepanning a pyramidal portion of the inservice material including the strain gage and measuring the relieved strain in the material; c'. determining whether the material has been loaded above the yield point stress while in service; and d'. furnishing a specimen from the pyramidal portion for the bending, measuring, and behavior determining steps b, c, and d.
Claim 48
Dependent Claim
20 words
A process according to claim 46 wherein the mechanical behavior to be determined is the residual plastic stress and strain.
Claim 49
Dependent Claim
42 words
A process as in claim 1 wherein the mechanical behavior determining step d comprises: e. computing the load/deflection function corresponding to at least one trial stress/strain function, and f. comparing the computed load/deflection function with the load/deflection function measured in step c.
Claim 50
Dependent Claim
112 words
A process as in claim 48 comprising also: g. repeating steps e and f for new trial stress/strain functions until a trail stress/strain function provides a computed load/deflection function that differs from the measured load/deflection function in the opposite direction from that of another computed load/deflection function, h. repeating steps e and f for a trial stress/strain function interpolated between the trial stress/strain function for which the computed load/deflection functions differ the least from the measured load/deflection function and in opposite directions therefrom, and i. repeating step h until a stress/strain function is determined for which the computed load/deflection function is within a selected range of tolerance from the measured load/deflection function.
Claim 51
Dependent Claim
38 words
A process as in claim 49 wherein the computing step e is carried out using an appropriate finite element computer code capable of modelling the non-linear material (constitutive), geometrical, and boundary conditions present during steps b and c.
Claim 52
Dependent Claim
30 words
A process as in claim 49 wherein the computing step e is carried out using the ABAQUS finite element computer code and the finite element friction-gap boundary condition model subroutine.
Claim 53
Dependent Claim
84 words
A process as in claim 48 comprising also: g. repeating steps e and f for new trial stress/strain functions until a trial stress/strain function provides a computed load/deflection function that differs from the measured load/deflection function in the opposite direction from that of another computed load/deflection function, and j. determining the stress/strain function for the measured load/deflection function by interpolation between the trial stress/strain functions for which the computed load/deflection functions differ the least from the measured load/deflection function and in opposite directions therefrom.
Claim 54
Dependent Claim
15 words
A process as in claim 52 wherein the interpolation is carried out point by point.
Claim 55
Dependent Claim
17 words
A process as in claim 52 wherein the interpolation is carried out with an empirically determined algorithm.
Claim 56
Dependent Claim
38 words
A process as in claim 52 wherein the computing step e is carried out using an appropriate finite element computer code capable of modelling the non-linear material (constitutive), geometrical, and boundary conditions present during steps b and c.
Claim 57
Dependent Claim
30 words
A process as in claim 52 wherein the computing step e is carried out using the ABAQUS finite element computer code and the finite element friction-gap boundary condition model subroutine.
Claim 58
Dependent Claim
16 words
A process as in claim 48 wherein the trial stress/strain functions are expressible as mathematical relations.
Claim 59
Dependent Claim
17 words
A process as in claim 48 wherein the trial stress/strain functions are expressible as power law relations.
Claim 60
Dependent Claim
35 words
A process as in claim 58 wherein each power law relation has the general form σ=Kε.sup.n where σ=true stress ε=true strain n=strain-hardening exponent K=σ uts /n n =strength coefficient, σ uts =true ultimate tensile strength.
Claim 61
Dependent Claim
17 words
A process as in claim 48 wherein the trial stress/strain functions are expressed as a power series.
Claim 62
Dependent Claim
29 words
A process as in claim 60 wherein the power series has the general form σ=a.sub.o +a.sub.1 ε+a.sub.2 ε.sup.2 +- - -+a.sub.n ε.sup.n, where each a i is a constant.
Claim 63
Dependent Claim
30 words
A process as in claim 48 wherein the trial stress/strain function in step e is related to known behavior of the material or of a material having similar relevant characteristics.
Claim 64
Dependent Claim
66 words
A process as in claim 62 wherein the material is an alloy, and the known behavior is that of another alloy having the same base; or wherein the material has been irradiated, and the known behavior is that of similar material that has not been irradiated; or wherein the material has been irradiated, and the known behavior is that of similar material that has been irradiated.
Claim 65
Dependent Claim
35 words
A process as in claim 48 wherein the mechanical behavior determining step d is carried out substantially in accordance with FIG. 31 of the drawings hereof, and the description relating thereto in the foregoing specification.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-02-03 | 1989-08-05 | 1990-02-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-02-03 | 1993-08-05 | 1994-02-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-02-03 | 1997-08-05 | 1998-02-04 | $7700.00 | Window Closed / Lapsed |