CN103471935A - Test piece for fracture toughness of III type cracks - Google Patents
Test piece for fracture toughness of III type cracks Download PDFInfo
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- CN103471935A CN103471935A CN2013104054716A CN201310405471A CN103471935A CN 103471935 A CN103471935 A CN 103471935A CN 2013104054716 A CN2013104054716 A CN 2013104054716A CN 201310405471 A CN201310405471 A CN 201310405471A CN 103471935 A CN103471935 A CN 103471935A
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Abstract
The invention discloses a test piece for fracture toughness of III type cracks. The test piece is a rectangular flat-plate test piece; the length of the broad edge is more than the thickness and less than the length of the long edge; initial cracks are symmetrically arranged on the two sides in the broad edge direction of a flat plate; symmetric V-shaped edge cutting grooves are formed in the two sides in the thickness direction of the flat plate. According to the test piece, the fracture toughness of the III type cracks of a plastic material can be effectively and stably tested and a test can be finished on a universal test machine.
Description
Technical field
The invention belongs to solid mechanics basic mechanical characteristic test field, particularly a kind of test test specimen of III type crack fracture toughness.
Background technology
Material fracture toughness is a basic parameter of fracturing mechanics, is the tolerance that material stops macroscopic cracking unstable propagation ability, is also the Roughness Parameter of material opposing brittle rupture.The size of it and crackle itself, shape and applied stress size have nothing to do.The intrinsic characteristic of material, only relevant with material itself, thermal treatment and processing technology.It is the critical value of stress intensity factor.The energy that before fracture commonly used, object absorbs or outer bound pair object institute work mean.
Basic fracture mode has I type, II type, III type.Opening mode fracture (open mode) is also named in the fracture of I type, is that a kind of danger the most is also to study the most deep fracture mode.Sliding mode fracture (slide mode) also is in the fracture of II type, and tearing mode fracture (twist mode) is also named in the fracture of III type, and they are all relevant with shear stress.Measurement about I type, II type fracture basic parameter has had significant progress, method of testing agrees that some has formed standard, as the compact tension specimen for measuring I type fragmentation parameters is tested, monolateral lancing-drawing experiment, Double-Notched stretching experiment, monolateral otch three-point bending test, centre burst compression test etc.; For single shear experiment, the double-shear experiment of measuring II type fragmentation parameters, side openings three-point bending test etc.
Research and comparison about III type crack initiation is few, fails to form unified standard and method.The method of current use has: the chute type crackle is sheared (crack rail shear), semi-girder cracking (split cantilever beam) shearing, the limit crackle reverses (edge crack torsion), Incline Crack stretching (slant notch tension) etc., yet there is certain defect in these methods.What have can not provide pure shear stress, fracture is no longer simple III type fracture, becomes Mixed Mode Fracture and (sees A comparison of Mode III threshold under simple shear and RCF conditions, M.G.Tarantino, S.Beretta, S.Foletti, J.Lai, Engineering Fracture Mechanics, Volume78, Issue8, May2011, Pages1742 – 1755).What have is the restriction that is subject to test specimen and material self character, and I type, the fracture of II type occur in experimentation, causes experiment success rate low.Perhaps experiment needs proprietary experimental facilities, on universal testing machine, completes again.Document " Design and analysis of a new six-point edge crack torsion (6ECT) specimen for mode III interlaminar fracture characterisation " (A.B.Pereira, A.B.de Morais, M.F.S.F.de Moura, Composites Part A:Applied Science and Manufacturing, Volume42, Issue2, February2011, Pages131 – 139), 6 border load tests of a kind of lath-shaped test specimen have been proposed, in test, load(ing) point is more, and be unfavorable for asymmetrical load, therefore be necessary test test specimen and the experimental technique of III type crack fracture toughness are made to improvement.
Summary of the invention
The object of the present invention is to provide a kind of grade enough effective and easy-operating for measuring the test test specimen of III type crack fracture toughness.
The technical solution that realizes the object of the invention is:
A kind of test test specimen of III type crack fracture toughness, test specimen is the rectangular flat plate test specimen, long limit ﹥ broadside ﹥ thickness, the symmetria bilateralis on dull and stereotyped broadside arranges initial crack, and symmetrical V-type limit grooving is set on the both sides of slab-thickness direction.
The present invention compared with prior art, its remarkable advantage:
(1) utilize the test test specimen of III type crack fracture toughness of the present invention, can guarantee relative pure shear strain, guarantee that test specimen is fractured into III type crack fracture.
(2) the simple easy operating of test specimen of the present invention and processing, experiment is simple, is conducive to less experiment fees.
(3) utilize test specimen of the present invention to coordinate special-purpose fixture can on universal testing machine, complete the test of fracture toughness, thereby experimental system is simple, is conducive to eliminate the systematic error of test.
(4) test specimen of the present invention, before test specimen does not rupture, can be measured the modulus of shearing of material.
(5) utilize the test result of test specimen of the present invention can be directly used in the test specimen fracture toughness, and do not need intermediate conversion steps, calculate simply.
Below in conjunction with accompanying drawing, the present invention is described in further detail.
The accompanying drawing explanation
Fig. 1 is the front view of the test test specimen of III type crack fracture toughness of the present invention.
Fig. 2 is the side view of the test test specimen of III type crack fracture toughness of the present invention.
Fig. 3 is axonometric drawing and the power loading figure of the test test specimen of III type crack fracture toughness of the present invention.
Embodiment
The test test specimen of a kind of III type of the present invention crack fracture toughness, test specimen is the rectangular flat plate test specimen, long limit ﹥ broadside ﹥ thickness, the symmetria bilateralis on dull and stereotyped broadside arranges initial crack, and symmetrical V-type limit grooving is set on the both sides of slab-thickness direction.The length of test specimen and width are more than the octuple of thickness.The degree of depth of the V-type limit grooving of test specimen is less than 1/4 of specimen thickness.The length of the initial crack of test specimen is less than 1/4 of specimen thickness.
In conjunction with Fig. 1, Fig. 2, Fig. 3, the test of III type crack fracture toughness adopts the method for the power loadings such as 2 support, at 2.Test specimen is positioned at the xy plane, and initial crack and limit grooving are parallel to the x axle.Two strong points that a, a ' are test specimen, b, b ' are the power load(ing) point.Anchorage force is parallel to the z axle, be parallel to-z of loading force P direction axle.This loading method can guarantee to provide pure shear stress for test specimen.Test specimen is plate Double-Notched test specimen, and the test specimen symmetria bilateralis initial sharp preset crackle that distributing, with the rift direction of pilot specimen; The preset limit of test specimen side grooving, guarantee that the test specimen fracture crack is along x axle expansion expansion.
The test test specimen of III type crack fracture toughness of the present invention, the length of test specimen and width are greater than 8 times of thickness.
The test test specimen of III type crack fracture toughness of the present invention, the preset limit grooving of test specimen is V-type point limit grooving, with the guiding crack fracture.
The test test specimen of III type crack fracture toughness of the present invention, the limit cutting groove depth of test specimen must not be greater than 1/4 of specimen thickness, to guarantee test specimen, enough physical strengths is arranged.
The test test specimen of III type crack fracture toughness of the present invention, its experiment loading method is the diagonal angle asymmetrical load, on different diagonal line, loading direction is contrary, take and guarantees to provide pure shear stress as test specimen.
The test test specimen of III type crack fracture toughness of the present invention, its experiment loading force and anchorage force direction are all perpendicular to the test specimen plane, and opposite direction, to guarantee that the shear stress direction is perpendicular to direction of crack propagation.
The test test specimen of III type crack fracture toughness of the present invention, simultaneously can be for testing modulus of shearing for the test of III type crack fracture toughness.
The test test specimen use procedure of III type crack fracture toughness of the present invention is as follows: test specimen be placed horizontally at supporting seat on, the supporting seat fulcrum contacts with a, a ' point, guarantee that test specimen is vertical with the support direction, then experimental facilities loads test specimen, two load(ing) points act on b, b ' point, and loading direction is perpendicular to the test specimen plane.This kind of loading method can guarantee that the pure shear that provides relative loads, and has also guaranteed the simple of experimental technique.
Facts have proved, the test test specimen of III type crack fracture toughness can be used in the test of III type crack fracture toughness, and experiment success rate has higher success ratio with respect to other experimental technique, waits simultaneously and guarantees that pure shear loads, operation is simple, is conducive to the elimination of experimental system error.
Embodiment 1:
By the test test specimen of III type crack fracture toughness of the present invention, be applied to, in the III type crack fracture toughness measurement of double base propellant, make the test test specimen of the plate III type crack fracture toughness of double base propellant.For guaranteeing the validity of test, according to the present invention in the explanation of claim, the long 100mm of test specimen, wide 80mm.Because density of material is less, and rigidity is relatively large, therefore the desirable thickness 8mm of thickness, Initial crack length is got 10mm, because the less toughness of the modulus of double base propellant is less, the V-type cutting groove depth is got 1mm.Facts have proved, the test test specimen of invention III type crack fracture toughness can well be applied to the III type crack fracture toughness of double base propellant and measure, and test specimen disconnects along the grooving direction, has proved and has been fractured into the III type, is loaded as shear strain.
Embodiment 2:
By the test test specimen of III type crack fracture toughness of the present invention, be applied to, in the III type crack fracture toughness measurement of No. 45 steel, make the test test specimen of the plate III type crack fracture toughness of No. 45 steel.For guaranteeing the validity of test, according to the present invention in the explanation of claim, the long 100mm of test specimen, wide 80mm.Because the density of steel is larger, test result easily is subject to the impact of material deadweight, therefore specimen thickness is got 8mm, and Initial crack length 10mm, because the modulus of steel is larger, and toughness is larger, therefore the V-type cutting groove depth is got 2mm.Facts have proved, the test test specimen of invention III type crack fracture toughness can well be applied to the III type crack fracture toughness of No. 45 steel and measure, and test specimen disconnects along the grooving direction, has proved and has been fractured into the III type, is loaded as shear strain.
Claims (4)
1. the test test specimen of an III type crack fracture toughness, it is characterized in that: test specimen is the rectangular flat plate test specimen, long limit ﹥ broadside ﹥ thickness, the symmetria bilateralis on dull and stereotyped broadside arranges initial crack, and symmetrical V-type limit grooving is set on the both sides of slab-thickness direction.
2. the test test specimen of a kind of III type crack fracture toughness according to claim 1, it is characterized in that: the length of described test specimen and width are more than the octuple of thickness.
3. the test test specimen of a kind of III type crack fracture toughness according to claim 1, it is characterized in that: the degree of depth of the V-type limit grooving of described test specimen is less than 1/4 of specimen thickness.
4. the test test specimen of a kind of III type crack fracture toughness according to claim 1, is characterized in that, the length of the initial crack of described test specimen is less than 1/4 of specimen thickness.
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106404562A (en) * | 2016-10-08 | 2017-02-15 | 四川大学 | Test piece for testing rock II-type dynamic fracture toughness and testing method |
| CN106404535A (en) * | 2016-10-08 | 2017-02-15 | 四川大学 | Test piece component for testing rock III-type fracture toughness and testing method |
| CN106546477A (en) * | 2016-10-08 | 2017-03-29 | 四川大学 | For the test specimen component and method of testing of the test of fragile material type III Dynamic Fracture Toughness |
| CN114112660A (en) * | 2021-09-03 | 2022-03-01 | 北京理工大学 | Sample suitable for testing dynamic fracture toughness of explosive welding interface |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4895027A (en) * | 1988-01-19 | 1990-01-23 | Battelle Development Corporation | Determining plane strain fracture toughness and the J-Integral for solid materials using stress field modified miniature specimens |
| US6053034A (en) * | 1998-10-09 | 2000-04-25 | Advanced Micro Devices, Inc. | Method for measuring fracture toughness of thin films |
| WO2004015398A1 (en) * | 2002-08-08 | 2004-02-19 | Monash University | Method and apparatus for determining fracture toughness |
| UA13208U (en) * | 2005-10-10 | 2006-03-15 | Univ Nat Agrarian | Method for determining the crack resistance of rolled sheet product |
| CN103217346A (en) * | 2013-04-01 | 2013-07-24 | 北京航空航天大学 | Method for measuring high-temperature creep crack growth threshold value of material |
| CN203479643U (en) * | 2013-09-06 | 2014-03-12 | 南京理工大学 | Test piece for testing fracture toughness of type-III cracks |
-
2013
- 2013-09-06 CN CN2013104054716A patent/CN103471935A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4895027A (en) * | 1988-01-19 | 1990-01-23 | Battelle Development Corporation | Determining plane strain fracture toughness and the J-Integral for solid materials using stress field modified miniature specimens |
| US6053034A (en) * | 1998-10-09 | 2000-04-25 | Advanced Micro Devices, Inc. | Method for measuring fracture toughness of thin films |
| WO2004015398A1 (en) * | 2002-08-08 | 2004-02-19 | Monash University | Method and apparatus for determining fracture toughness |
| UA13208U (en) * | 2005-10-10 | 2006-03-15 | Univ Nat Agrarian | Method for determining the crack resistance of rolled sheet product |
| CN103217346A (en) * | 2013-04-01 | 2013-07-24 | 北京航空航天大学 | Method for measuring high-temperature creep crack growth threshold value of material |
| CN203479643U (en) * | 2013-09-06 | 2014-03-12 | 南京理工大学 | Test piece for testing fracture toughness of type-III cracks |
Non-Patent Citations (2)
| Title |
|---|
| 张子龙等: "《中华人民共和国航空工业标准 HB 7237-95 复合材料层合板面内剪切试验方法》", 13 December 1995, 航空工业出版社, article "《中华人民共和国航空工业标准 HB 7237-95 复合材料层合板面内剪切试验方法》", pages: 1-7 * |
| 陈永清: "I、II、III型混合模态下的断裂准则", 《万方学位论文数据库》, 27 February 2006 (2006-02-27) * |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106404562A (en) * | 2016-10-08 | 2017-02-15 | 四川大学 | Test piece for testing rock II-type dynamic fracture toughness and testing method |
| CN106404535A (en) * | 2016-10-08 | 2017-02-15 | 四川大学 | Test piece component for testing rock III-type fracture toughness and testing method |
| CN106546477A (en) * | 2016-10-08 | 2017-03-29 | 四川大学 | For the test specimen component and method of testing of the test of fragile material type III Dynamic Fracture Toughness |
| CN106546477B (en) * | 2016-10-08 | 2018-11-23 | 四川大学 | Test specimen component and test method for the test of fragile material type III Dynamic Fracture Toughness |
| CN106404535B (en) * | 2016-10-08 | 2018-12-11 | 四川大学 | Test specimen component and test method for rock type III fracture toughness testing |
| CN114112660A (en) * | 2021-09-03 | 2022-03-01 | 北京理工大学 | Sample suitable for testing dynamic fracture toughness of explosive welding interface |
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Application publication date: 20131225 |