1、Designation: D 7137/D 7137M 07Standard Test Method forCompressive Residual Strength Properties of DamagedPolymer Matrix Composite Plates1This standard is issued under the fixed designation D 7137/D 7137M; the number immediately following the designation indicates theyear of original adoption or, in
2、the case of revision, the year of last revision. A number in parentheses indicates the year of lastreapproval. A superscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers compression residual strengthproperties of multidirectional
3、 polymer matrix composite lami-nated plates, which have been subjected to quasi-static inden-tation per Test Method D 6264/D 6264M or drop-weight im-pact per Test Method D 7136/D 7136M prior to application ofcompressive force. The composite material forms are limited tocontinuous-fiber reinforced po
4、lymer matrix composites withmultidirectional fiber orientations, and which are both symmet-ric and balanced with respect to the test direction. The range ofacceptable test laminates and thicknesses is defined in 8.2.NOTE 1When used to determine the residual strength of drop-weightimpacted plates, th
5、is test method is commonly referred to as theCompression After Impact, or CAI, method.1.2 The method utilizes a flat, rectangular composite plate,previously subjected to a damaging event, which is testedunder compressive loading using a stabilization fixture.NOTE 2The damage tolerance properties obt
6、ained are particular to thetype, geometry and location of damage inflicted upon the plate.1.3 The properties generated by this test method are highlydependent upon several factors, which include specimen ge-ometry, layup, damage type, damage size, damage location,and boundary conditions. Thus, resul
7、ts are generally notscalable to other configurations, and are particular to thecombination of geometric and physical conditions tested.1.4 This test method can be used to test undamaged polymermatrix composite plates, but historically such tests havedemonstrated a relatively high incidence of undesi
8、rable failuremodes (such as end crushing). Test Method D 6641/D 6641Mis recommended for obtaining compressive properties of un-damaged polymer matrix composites.1.5 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard. Within the text theinch-pound units
9、are shown in brackets. The values stated ineach system are not exact equivalents; therefore, each systemmust be used independently of the other. Combining valuesfrom the two systems may result in nonconformance with thestandard.1.6 This standard does not purport to address all of thesafety concerns,
10、 if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 792 Test Methods for Density and Specific
11、Gravity (Rela-tive Density) of Plastics by DisplacementD 883 Terminology Relating to PlasticsD 3171 Test Methods for Constituent Content of CompositeMaterialsD 3878 Terminology for Composite MaterialsD 5229/D 5229M Test Method for Moisture AbsorptionProperties and Equilibrium Conditioning of Polymer
12、 Ma-trix Composite MaterialsD 5687/D 5687M Guide for Preparation of Flat CompositePanels with Processing Guidelines for Specimen Prepara-tionD 6264/D 6264M Test Method for Measuring the DamageResistance of a Fiber-Reinforced Polymer-Matrix Com-posite to a Concentrated Quasi-Static Indentation ForceD
13、 6641/D 6641M Test Method for Determining the Com-pressive Properties of Polymer Matrix Composite Lami-nates Using a Combined Loading Compression (CLC) TestFixtureD 7136/D 7136M Test Method for Measuring the DamageResistance of a Fiber-Reinforced Polymer Matrix Com-posite to a Drop-Weight Impact Eve
14、ntE4 Practices for Force Verification of Testing MachinesE6 Terminology Relating to Methods of Mechanical Test-ing1This test method is under the jurisdiction of ASTM Committee D30 onComposite Materials and is the direct responsibility of Subcommittee D30.05 onStructural Test Methods.Current edition
15、approved Nov. 15, 2007. Published December 2007. Originallyapproved in 2005. Last previous edition approved in 2005 as D 7137/D 7137M-05e1.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume
16、 information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.Copyright by ASTM Intl (all rights reserved); Wed Dec 19 01:48:13 EST 2007Downloaded/printed byGuo Dehua (C
17、NIS) pursuant to License Agreement. No further reproductions authorized.E 122 Practice for Calculating Sample Size to Estimate,With Specified Precision, the Average for a Characteristicof a Lot or ProcessE 177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE 456 Terminology Rela
18、ting to Quality and StatisticsE 1309 Guide for Identification of Fiber-ReinforcedPolymer-Matrix Composite Materials in DatabasesE 1434 Guide for Recording Mechanical Test Data of Fiber-Reinforced Composite Materials in Databases2.2 Military Standards:MIL-HDBK-17-3F Composite Materials Handbook, Vol-
19、ume 3Polymer Matrix Composites Materials Usage,Design and Analysis3MIL-HDBK-728/1 Nondestructive Testing4MIL-HDBK-731A Nondestructive Testing Methods ofComposite MaterialsThermography4MIL-HDBK-732A Nondestructive Testing Methods ofComposite MaterialsAcoustic Emission4MIL-HDBK-733A Nondestructive Tes
20、ting Methods ofComposite MaterialsRadiography4MIL-HDBK-787A Nondestructive Testing Methods ofComposite MaterialsUltrasonics4NASA Reference Publication 1092 Standard Tests forToughened Resin Composites, Revised Edition, July198353. Terminology3.1 DefinitionsTerminology D 3878 defines terms relatingto
21、 composite materials. Terminology D 883 defines termsrelating to plastics. Terminology E6defines terms relating tomechanical testing. Terminology E 456 and Practice E 177define terms relating to statistics. In the event of a conflictbetween terms, Terminology D 3878 shall have precedenceover the oth
22、er standards.3.2 Definitions of Terms Specific to This StandardIf theterm represents a physical quantity, its analytical dimensionsare stated immediately following the term (or letter symbol) infundamental dimension form, using the following ASTMstandard symbology for fundamental dimensions, shownwi
23、thin square brackets: M for mass, L for length, T fortime, u for thermodynamic temperature, and nd for non-dimensional quantities. Use of these symbols is restricted toanalytical dimensions when used with square brackets, as thesymbols may have other definitions when used without thebrackets.3.2.1 n
24、ominal value, na value, existing in name only,assigned to a measurable property for the purpose of conve-nient designation. Tolerances may be applied to a nominalvalue to define an acceptable range for the property.3.2.2 principal material coordinate system, na coordinatesystem with axes that are no
25、rmal to the planes of symmetryinherent to a material.3.2.2.1 DiscussionCommon usage, at least for Cartesianaxes (123, xyz, and so forth), generally assigns the coordinatesystem axes to the normal directions of planes of symmetry inorder that the highest property value in a normal direction (forelast
26、ic properties, the axis of greatest stiffness) would be 1 orx, and the lowest (if applicable) would be 3 or z. Anisotropicmaterials do not have a principal material coordinate systemdue to the total lack of symmetry, while, for isotropic materials,any coordinate system is a principal material coordi
27、natesystem. In laminated composites, the principal material coor-dinate system has meaning only with respect to an individualorthotropic lamina. The related term for laminated compositesis “reference coordinate system.”3.2.3 reference coordinate system, na coordinate systemfor laminated composites u
28、sed to define ply orientations. Oneof the reference coordinate system axes (normally the Carte-sian x-axis) is designated the reference axis, assigned aposition, and the ply principal axis of each ply in the laminateis referenced relative to the reference axis to define the plyorientation for that p
29、ly.3.2.4 specially orthotropic, adja description of an ortho-tropic material as viewed in its principal material coordinatesystem. In laminated composites, a specially orthotropic lami-nate is a balanced and symmetric laminate of the 0i/90jnsfamily as viewed from the reference coordinate system, suc
30、hthat the membrane-bending coupling terms of the laminateconstitutive relation are zero.3.3 Symbols:A = cross-sectional area of a specimenCV = coefficient of variation statistic of a sample populationfor a given property (in percent)D = damage diameterECAI= effective compressive modulus in the test
31、directionFCAI= ultimate compressive residual strength in the testdirectionh = specimen thicknessl = specimen lengthn = number of specimens per sample populationN = number of plies in laminate under testPmax= maximum force carried by test specimen prior tofailureSn-1= standard deviation statistic of
32、a sample population fora given propertyw = specimen widthxi= test result for an individual specimen from the samplepopulation for a given propertyx= mean or average (estimate of mean) of a sample popu-lation for a given property4. Summary of Test Method4.1 A uniaxial compression test is performed us
33、ing a bal-anced, symmetric laminated plate, which has been damagedand inspected prior to the application of compressive force.The damage state is imparted through out-of-plane loadingcaused by quasi-static indentation or drop-weight impact.3Available from U.S. Army Research Laboratory, Materials Dir
34、ectorate, Aber-deen Proving Ground, MD 21001.4Available from U.S. Army Materials Technology Laboratory, Watertown, MA02471.5Available from National Aeronautics and Space Administration (NASA)-Langley Research Center, Hampton, VA 23681-2199.D 7137/D 7137M 072Copyright by ASTM Intl (all rights reserve
35、d); Wed Dec 19 01:48:13 EST 2007Downloaded/printed byGuo Dehua (CNIS) pursuant to License Agreement. No further reproductions authorized.FIG. 1 Schematic of Compressive Residual Strength Support Fixture with Specimen in PlaceFIG. 2 Support Fixture AssemblyD 7137/D 7137M 073Copyright by ASTM Intl (al
36、l rights reserved); Wed Dec 19 01:48:13 EST 2007Downloaded/printed byGuo Dehua (CNIS) pursuant to License Agreement. No further reproductions authorized.4.1.1 Quasi-Static IndentationThe rectangular plate isdamaged due to application of an out-of-plane static indenta-tion force in accordance with Te
37、st Method D 6264/D 6264M.4.1.2 Drop-Weight ImpactThe rectangular plate is dam-aged due to application of an out-of-plane drop-weight impactin accordance with Test Method D 7136/D 7136M.4.2 The damaged plate is installed in a multi-piece supportfixture, that has been aligned to minimize loading eccen
38、tricitiesand induced specimen bending. The specimen/fixture assemblyis placed between flat platens and end-loaded under compres-sive force until failure. Applied force, crosshead displacement,and strain data are recorded while loading.4.3 Preferred failure modes pass through the damage in thetest sp
39、ecimen. However, acceptable failures may initiate awayfrom the damage site, in instances when the damage producesa relatively low stress concentration or if the extent of damageis small, or both. Unacceptable failure modes are those relatedto load introduction by the support fixture, local edge supp
40、ortconditions, and specimen instability (unless the specimen isdimensionally representative of a particular structural applica-tion).5. Significance and Use5.1 Susceptibility to damage from concentrated out-of-planeforces is one of the major design concerns of many structuresmade of advanced composi
41、te laminates. Knowledge of thedamage resistance and damage tolerance properties of alaminated composite plate is useful for product developmentand material selection.5.2 The residual strength data obtained using this testmethod is most commonly used in material specifications andresearch and develop
42、ment activities. The data are not intendedFIG. 3 Support Fixture Base Plate (Inch-Pound Version)FIG. 4 Support Fixture Base Plate (SI Version)D 7137/D 7137M 074Copyright by ASTM Intl (all rights reserved); Wed Dec 19 01:48:13 EST 2007Downloaded/printed byGuo Dehua (CNIS) pursuant to License Agreemen
43、t. No further reproductions authorized.for use in establishing design allowables, as the results arespecific to the geometry and physical conditions tested and aregenerally not scalable to other configurations. Its usefulness inestablishing quality assurance requirements is also limited, dueto the i
44、nherent variability of induced damage, as well as thedependency of damage tolerance response upon the pre-existent damage state.5.3 The properties obtained using this test method canprovide guidance in regard to the anticipated damage tolerancecapability of composite structures of similar material,
45、thick-ness, stacking sequence, and so forth. However, it must beunderstood that the damage tolerance of a composite structureis highly dependent upon several factors including geometry,stiffness, support conditions, and so forth. Significant differ-ences in the relationships between the existent dam
46、age stateand the residual compressive strength can result due todifferences in these parameters. For example, residual strengthand stiffness properties obtained using this test method wouldmore likely reflect the damage tolerance characteristics of anun-stiffened monolithic skin or web than that of
47、a skin attachedto substructure which resists out-of-plane deformation. Simi-larly, test specimen properties would be expected to be similarto those of a panel with equivalent length and width dimen-sions, in comparison to those of a panel significantly largerthan the test specimen.5.4 The reporting
48、section requires items that tend to influ-ence residual compressive strength to be reported; theseinclude the following: material, methods of material fabrica-tion, accuracy of lay-up orientation, laminate stacking se-quence and overall thickness, specimen geometry, specimenpreparation, specimen con
49、ditioning, environment of testing,void content, volume percent reinforcement, type, size andlocation of damage (including method of non-destructiveinspection), specimen/fixture alignment and gripping, time attemperature, and speed of testing.5.5 Properties that result from the residual strength assess-ment include the following: compressive residual strengthFCAI, compressive force as a function of crosshead displace-ment, and surface strains as functions of crosshead displace-ment.6. Interferences6.1 The response of a damaged specimen is dependent u
