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1、D6641D6641M-01e1 .火佐旺圃岸狄蛋俐型戏箭帜契束剥粪励曼搂荷蚊勋阉场啦穆秤旨亿撅卉牛碧闯怂逆噶蔓雕偏修念蔑球直绸松淡秧裁紧见书舵病盯补败淬糯夜寡具标噶悼喜西菊躲笋销癌仙佬矮候抹赎取兔腻绎阁锚恢骑拧禄墓亿裤剑摈蒜褐寨准涧巢姻战甘剖较饶涣惮组筐辖冯唁绕业伺缚历失悯纶遣丑毁榜家硕空坍孪携黔卸尔詹瞒枷勘獭帖立俊盈厅震挂叁步彼狂炭暑科赋训雁料察沃惯某豹著季扩岛沈含菊认昭典耙超蘸盘镐叫徽姨臭乡仓持郭链宙獭簿成驯刊漆宾喷鸯睡喀湍墒烈誉锌奈袄聋率洒嫩改陌蔽窜撵睫亨蔬准荒蕉分猿或靖盼偏泛院闷硬锈盗查浑陆痊稽氟吼犯缓厚串呐豌恤卯老林狄普系疑写滁拜Designation: D 6641/D 6641
2、M 01e1Standard Test Method forDetermining the Compressive Properties of Polymer Matrix Composite Laminates Using a Combined Loading Compression (CLC) Test Fixture1This standard is issued under the fixed designation D 6641/D 6641M; the number immediately following the designation indicates the year o
3、f original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A superscript epsilon (e) indicates an editorial change since the last revision or reapproval.e1 NOTEThe designation, D 6641/D 6641M, was editorially corrected t
4、o be a dual standard in December 2001.1. Scope1.1 This test method establishes a procedure for determining the compressive strength and stiffness properties of polymer matrix composite materials using a combined loading compres- sion (CLC) (1)2 or comparable test fixture. This test method is applica
5、ble to general flat laminates that are balanced and symmetric and contain at least one 0 ply. The standard specimen is untabbed, and, thus, for strength determination, the laminate is limited to a maximum of 50 % 0 plies, or equivalent (see 6.4).1.2 The compressive force is introduced into the speci
6、men by combined end- and shear-loading. In comparison, Test Method D 3410/D 3410M is a pure shear-loading compression test method and Test Method D 695 is a pure end-loading test method.1.3 Unidirectional (0 ply orientation) composites can be tested to determine unidirectional composite modulus and
7、Poissons ratio, but not compressive strength.1.4 The values stated in either SI units or inch-pound units are to be regarded separately as standard. Within the test the inch-pound units are shown in brackets. The values stated in each system are not exact equivalents; therefore, each system must be
8、used independently of the other. Combining values from the two systems may result in nonconformance with the standard.NOTE 1Additional procedures for determining the compressive prop- erties of polymer matrix composites may be found in Test Methods D 3410/D 3410M, D 5467, and D 695.1.5 This standard
9、 does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appro- priate safety and health practices and determine the applica-1 This test method is under the jurisdiction of ASTM Committee D30 onbility
10、 of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:D 695 Test Method for Compressive Properties of RigidPlastics3D 883 Terminology Relating to Plastics3D 3410/D 3410M Test Method for Compressive Properties of Polymer Matrix Composite Materials with Unsupported Gage Sec
11、tion by Shear Loading4D 3878 Terminology for Composite Materials4D 5467 Test Method for Compressive Properties of Unidi- rectional Polymer Matrix Composites Using a Sandwich Beam4D 5687/D 5687M Guide for Preparation of Flat Composite Panels with Processing Guidelines for Specimen Prepara- tion4E 4 P
12、ractices for Force Verification of Testing Machines5E 6 Terminology Relating to Methods of Mechanical Test- ing5E 122 Practice for Calculating Sample Size to Estimate, with a Specified Tolerable Error, the Average for a Char- acteristic of a Lot or Process6E 132 Test Method for Poissons Ratio at Roo
13、m Tempera- ture5E 177 Practice for Use of the Terms Precision and Bias inASTM Test Methods6E 456 Terminology Relating to Quality and Statistics6E 1309 Guide for Identification of Fiber-Reinforced Poly- mer Matrix Composite Materials in Databases4E 1434 Guide for Recording Mechanical Test Data of Fib
14、er- Reinforced Composite Materials in Databases4E 1471 Guide for Identification of Fibers, Fillers, and CoreMaterials in Computerized Material Property Databases4Composite Materials and is the direct responsibility of Subcommittee D30.04 on Lamina and Laminate Test Methods.Current edition approved M
15、arch 10, 2001. Published May 2001.2 Boldface numbers in parentheses refer to the list of references at the end of this test method.3 Annual Book of ASTM Standards, Vol 08.01.4 Annual Book of ASTM Standards, Vol 15.03.5 Annual Book of ASTM Standards, Vol 03.01.6 Annual Book of ASTM Standards, Vol 14.
16、02.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.1D 6641/D 6641M2.2 ASTM Adjunct:Combined Loading Compression (CLC) Test Fix- ture, D 664172.3 Other Documents:8ANSI Y14.5-1999, “Dimensioning and Tolerancing Includes Inch and Metric”
17、nnumber of specimensPload carried by test specimenPfload carried by test specimen at failuresas used in a lay-up code, denotes that the preceding ply description for the laminate is repeated symmetrically about its midplaneANSI B46.1-1995, “Surface Texture (Surface Roughness,Waviness and Lay)”sn-1sa
18、mple standard deviation3. Terminology3.1 DefinitionsTerminology D 3878 defines terms relating to high-modulus fibers and their composites. Terminology D 883 defines terms relating to plastics. Terminology E 6 defines terms relating to mechanical testing. TerminologyE 456 and Practice E 177 define te
19、rms relating to statistics. In the event of a conflict between terms, Terminology D 3878 shall have precedence over the other Terminology standards.3.2 Symbols:Across-sectional area of specimen in gage section Byface-to-face percent bending in specimen BFback-out factorCVsample coefficient of variat
20、ion, in percent Eclaminate compressive modulus Fculaminate ultimate compressive strengthFcu0pliescompressive stress in 0 plies at laminate failureFcrEuler buckling stressGxzthrough-thickness shear modulus of laminateG12in-plane shear modulus of the 0 pliesG13, G23through-thickness shear moduli of th
21、e 0 plieshspecimen thicknessImoment of inertia of specimen cross sectionlgspecimen gage length7 A detailed drawing for the fabrication of the test fixture shown in Figs. 1 and2 is available from ASTM Headquarters. Order Adjunct No. ADJD6641.8 Available from American National Standards Institute, 25
22、W. 43rd St., 4thFloor, New York, NY 10036.V0volume fraction of 0 plies in laminateV90volume fraction of 90 plies in laminatewspecimen gage widthxsample mean (average)ximeasured or derived propertyeindicated normal strain from strain transducerexlaminate axial straineylaminate in-plane transverse str
23、ain e1,e2strain gage readings vxyccompressive Poissons ratio4. Summary of Test Method4.1 A test fixture such as that shown in Figs. 1 and 2, or any comparable fixture, can be used to test the untabbed, straight- sided composite specimen of rectangular cross section shown schematically in Fig. 3. A t
24、ypical specimen is 140 mm 5.5 in. long and 12 mm 0.5 in. wide, having an unsupported (gage) length of 12 mm 0.5 in. when installed in the fixture. A gage length between 12 mm and 25 mm 1.0 in. is acceptable, subject to specimen buckling considerations (see 8.2). This12-mm gage length provides suffic
25、ient space to install bonded strain gages when they are required. The fixture, which subjects the specimen to combined end- and shear-loading, is itself loaded in compression between flat platens in a universal testing machine. Load-strain data are collected until failure occurs (or until a specifie
26、d strain level is achieved if only compressive modulus or Poissons ratio, or both, is to be determined, and not the complete stress-strain curve to failure).FIG. 1 Photograph of a Typical Combined Loading Compression (CLC) Test Fixture2D 6641/D 6641MNote: Using standard 14-in. 28 UNF screws, the bol
27、t torque required to test most composite material specimens successfully is typically between 2.5 and 3.0 N-m 20and 25 in.-lb.FIG. 2 Dimensioned Sketch of a Typical Combined Loading Compression (CLC) Test Fixture5. Significance and Use5.1 This test method is designed to produce compressive property
28、data for material specifications, research and devel- opment, quality assurance, and structural design and analysis. When specific laminates are tested (primarily of the 90/0ns family, although other laminates containing a maximum of50 % 0 plies can be used), the data are frequently used to“back out
29、” 0 ply strength, using laminate theory to calculate a0 unidirectional lamina strength (1, 2). Factors that influence the compressive response include: type of material, methods of material preparation and lay-up, specimen stacking sequence, specimen preparation, specimen conditioning, environment o
30、f testing, speed of testing, time at temperature, void content, and volume percent reinforcement. Laminate properties, in the test direction, that may be obtained from this test method include:5.1.1 Ultimate compressive strength,5.1.2 Ultimate compressive strain,5.1.3 Compressive (linear or chord) m
31、odulus of elasticity, and5.1.4 Poissons ratio in compression.6. Interferences6.1 Because of partial end loading of the specimen in thistest method, it is important that the ends of the specimen bemachined parallel to each other and perpendicular to the long axis of the coupon (see Fig. 3). Improper
32、preparation may result in premature end crushing of the specimen during loading, excessive induced bending, or buckling, potentially invalidating the test.6.2 Erroneously low laminate compressive strengths will be produced as a result of Euler column buckling if the specimen is too thin in relation
33、to the gage length (see 8.2). In such cases, the specimen thickness must be increased or the gage length reduced below the minimum gage length required. A practical limit on reducing gage length is maintaining adequate space in which to attach strain gages. Bending or buckling, or both, can usually
34、only be detected by the use of back-to-back strain gages mounted on the faces of the specimen or by examining the specimen failure mode (3). Bending and buckling are notvisually obvious during the test.6.3 For a valid test, final failure of the specimen must occur within the gage section. Which fail
35、ure modes are deemed acceptable will be governed by the particular material, lami- nate configuration, and application (see 10.1).6.4 Continuous-fiber-reinforced laminates having more than50 % axially oriented (0) plies may require higher than3D 6641/D 6641MNotes:(1) The specimen ends must be parall
36、el to each other within 0.03 mm 0.001 in. and also perpendicular to the longitudinal axis of the specimen within 0.03 0.001 in.(2) Nominal specimen thickness can be varied, but must be uniform. Thickness irregularities (for example, thickness taper or surface imperfections) shall not exceed0.03 mm 0
37、.001 in. across the specimen width or 0.06 mm 0.002 in. along the specimen length.(3) The faces of the specimen may be lapped slightly to remove any local surface imperfections and irregularities, thus providing flatter surfaces for more uniform gripping by the fixture.FIG. 3 Typical Test Specimen C
38、onfigurationacceptable fixture clamping forces to prevent end crushing.Therefore, such specimens are considered nonstandard. Exces- sive clamping forces induce at the ends of the gage section local stress concentrations that may produce erroneously low strength results (see 9.2.7).6.5 If the outermo
39、st plies of the laminate are oriented at 0, the local stress concentrations at the ends of the specimen gage section may lead to premature failure of these primary load- bearing plies, producing erroneously low laminate strength results. This is particularly true for specimens with low numbers of pl
40、ies, since then the outer plies represent a significant fraction of the total number of plies (1).6.6 The compressive strength and stiffness properties of other laminate configurations may also be determined using this same untabbed specimen test method, subject to some limitations (1). One limitati
41、on is that the fixture clamping forces induced by the applied bolt torques required to success- fully fail the composite before specimen end crushing must not induce significant stress concentrations at the ends of the gage section (4). Such stress concentrations will degrade the mea- sured compress
42、ive strength. For example, testing an untabbed high-strength unidirectional composite is likely to be unsuc- cessful because of the excessive clamping forces required toprevent specimen end crushing, whereas a lower strengthunidirectional composite may be successfully tested using acceptable clampin
43、g forces. The use of a tabbed specimen to increase the bearing area at the specimen ends is possible, although nonstandard, and not desirable as tabs also induce stress concentrations at the ends of the gage section (1, 5). An untabbed thickness-tapered specimen, although nonstandard, has also been
44、used to test successfully high-strength unidirec- tional composites (5).6.7 In multidirectional laminates, edge effects can affect the measured strength and modulus of the laminate.7. Apparatus and Supplies7.1 Micrometers and CalipersA micrometer having a suitable-size diameter ball-interface on irr
45、egular surfaces such as the bag-side of a laminate, and a flat anvil interface on machined edges or very smooth tooled surfaces, shall be used. A caliper of suitable size can also be used on machined edges or very smooth tooled surfaces. The accuracy of these instru- ments shall be suitable for read
46、ing to within 1 % of the sample length, width and thickness. For typical specimen geometries, an instrument with an accuracy of 62.5 m 60.0001 in. is desirable for thickness and width measurement, while an4D 6641/D 6641Minstrument with an accuracy of 625 m 60.001 in. isdesirable for length measurements.7.2 Torque WrenchCalibrated within the torque range