1、Designation: D 7137/D 7137M 05e1Standard 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, i
2、n 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.e1NOTEFig. 6 was editorially corrected in May 2005.1. Scope1.1 This test method covers compre
3、ssion residual strengthproperties of multidirectional polymer matrix composite lami-nated plates, which have been subjected to quasi-static inden-tation per Test Method D 6264 or drop-weight impact per TestMethod D 7136/D 7136M prior to application of compressiveforce. The composite material forms a
4、re limited to continuous-fiber reinforced polymer matrix composites with multidirec-tional fiber orientations, and which are both symmetric andbalanced with respect to the test direction. The range ofacceptable test laminates and thicknesses is defined in 8.2.NOTE 1When used to determine the residua
5、l strength of drop-weightimpacted plates, this 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 fixtu
6、re.NOTE 2The damage tolerance properties obtained 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 l
7、ocation,and boundary conditions. Thus, results 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 havedemons
8、trated a relatively high incidence of undesirable 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 st
9、andard. Within the text theinch-pound units 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 p
10、urport to address all of thesafety concerns, 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:2
11、D 792 Test Methods for Density and Specific 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 AbsorptionProper
12、ties and Equilibrium Conditioning of Polymer Ma-trix Composite LaminatesD 5687/D 5687M Guide for Preparation of Flat CompositePanels with Processing Guidelines for Specimen Prepara-tionD 6264 Test Method for Measuring the Damage Resistanceof a Fiber-Reinforced Polymer-Matrix Composite to aConcentrat
13、ed Quasi-Static Indentation ForceD 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-
14、posite to a Drop-Weight Impact EventE4 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 onStruct
15、ural Test Methods.Current edition approved April 1, 2005. Published April 2005.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page o
16、nthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.E 122 Practice for Calculation of Sample Size to Estimate,with a Secified Tolerable Error, the Average of Character-istic for a Lot or ProcessE 177 Practice for Use of
17、 the Terms Precision and Bias inASTM Test MethodsE 456 Terminology Relating to Quality and StatisticsE 1309 Guide for Identification of Fiber-Reinforced Poly-mer Matrix Composite Materials in DatabasesE 1434 Guide for Recording Mechanical Test Data of Fiber-Reinforced Composite Materials in Database
18、sE 1471 Guide for Identification of Fibers, Fillers and CoreMaterials in Computerized Material Property Databases2.2 Military Standards:MIL-HDBK-17-3F Composite Materials Handbook, Vol-ume 3Polymer Matrix Composites Materials Usage,Design and Analysis3MIL-HDBK-728/1 Nondestructive Testing4MIL-HDBK-7
19、31A Nondestructive Testing Methods ofComposite MaterialsThermography4MIL-HDBK-732A Nondestructive Testing Methods ofComposite MaterialsAcoustic Emission4MIL-HDBK-733A Nondestructive Testing Methods ofComposite MaterialsRadiography4MIL-HDBK-787A Nondestructive Testing Methods ofComposite MaterialsUlt
20、rasonics4NASA Reference Publication 1092 Standard Tests forToughened Resin Composites, Revised Edition, July198353. Terminology3.1 DefinitionsTerminology D 3878 defines terms relatingto composite materials. Terminology D 883 defines termsrelating to plastics. Terminology E6defines terms relating tom
21、echanical 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 other standards.3.2 Definitions of Terms Specific to This StandardIf theterm represents a physical quantity, its analy
22、tical dimensionsare stated immediately following the term (or letter symbol) infundamental dimension form, using the following ASTMstandard symbology for fundamental dimensions, shownwithin square brackets: M for mass, L for length, T fortime, u for thermodynamic temperature, and nd for non-dimensio
23、nal 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 nominal value, na value, existing in name only,assigned to a measurable property for the purpose of conve-nient desi
24、gnation. 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 normal to the planes of symmetryinherent to a material.3.2.2.1 DiscussionCommon usage, at least for Cartesianaxes (12
25、3, 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 (forelastic properties, the axis of greatest stiffness) would be 1 orx, and the lowest (if applicable) would be 3 or z. Anis
26、otropicmaterials 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 coordinatesystem. In laminated composites, the principal material coor-dinate system has meaning only with respect to an
27、individualorthotropic lamina. The related term for laminated compositesis “reference coordinate system.”3.2.3 reference coordinate system, na coordinate systemfor laminated composites used to define ply orientations. Oneof the reference coordinate system axes (normally the Carte-sian x-axis) is desi
28、gnated 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 ply.3.2.4 specially orthotropic, adja description of an ortho-tropic material as viewed in its principal material co
29、ordinatesystem. 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, suchthat the membrane-bending coupling terms of the laminateconstitutive relation are zero.3.3 Symbols:A = cross-secti
30、onal area of a specimenCV = coefficient of variation statistic of a sample populationfor a given property (in percent)D = damage diameter (see Fig. 13).ECAI= effective compressive modulus in the test directionFCAI= ultimate compressive residual strength in the testdirectionh = specimen thicknessl =
31、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 a sample population fora given propertyw = specimen widthxi= test result for an individual specimen
32、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 using a bal-anced, symmetric laminated plate, which has been damagedand inspected prior to the applica
33、tion 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 Directorate, Aber-deen Proving Ground, MD 21001.4Available from U.S. Army Materials Technology Laborato
34、ry, Watertown, MA02471.5Available from National Aeronautics and Space Administration (NASA)-Langley Research Center, Hampton, VA 23681-2199.D 7137/D 7137M 05e12FIG. 1 Schematic of Compressive Residual Strength Support Fixture with Specimen in PlaceFIG. 2 Support Fixture AssemblyD 7137/D 7137M 05e134
35、.1.1 Quasi-Static IndentationThe rectangular plate isdamaged due to application of an out-of-plane static indenta-tion force in accordance with Test Method D 6264.4.1.2 Drop-Weight ImpactThe rectangular plate is dam-aged due to application of an out-of-plane drop-weight impactin accordance with Test
36、 Method D 7136/D 7136M.4.1.3 Damage AssessmentIf not previously determinedafter the damaging event, the extent of damage is determinedusing non-destructive inspection (NDI) procedures as de-scribed in 11.4.4.2 The damaged plate is installed in a multi-piece supportfixture, that has been aligned to m
37、inimize loading eccentricitiesand 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
38、 damage in thetest specimen. 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 fix
39、ture, local edge supportconditions, and specimen instability (unless the specimen isdimensionally representative of a particular structural applica-tion).FIG. 3 Support Fixture Base Plate (Inch-Pound Version)FIG. 4 Support Fixture Base Plate (SI Version)D 7137/D 7137M 05e145. Significance and Use5.1
40、 Susceptibility to damage from concentrated out-of-planeforces is one of the major design concerns of structures madeof advanced composite laminates. Knowledge of the damageresistance and damage tolerance properties of a laminatedcomposite plate is useful for product development and materialselectio
41、n.5.2 The residual strength data obtained using this testmethod is most commonly used in material specifications andresearch and development activities. The data are not intendedfor use in establishing design allowables, as the results arespecific to the geometry and physical conditions tested and a
42、regenerally not scalable to other configurations. Its usefulness inestablishing quality assurance requirements is also limited, dueto the inherent variability of induced damage, as well as thedependency of damage tolerance response upon the pre-existent damage state.5.3 The properties obtained using
43、 this test method canprovide guidance in regard to the anticipated damage tolerancecapability of composite structures of similar material, thick-ness, stacking sequence, and so forth. However, it must beunderstood that the damage tolerance of a composite structureis highly dependent upon several fac
44、tors including geometry,stiffness, support conditions, and so forth. Significant differ-ences in the relationships between the existent damage stateand the residual compressive strength can result due todifferences in these parameters. For example, residual strengthand stiffness properties obtained
45、using this test method wouldmore likely reflect the damage tolerance characteristics of anun-stiffened monolithic skin or web than that of 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 wi
46、th equivalent length and width dimen-sions, in comparison to those of a panel significantly largerthan the test specimen.5.4 The reporting section requires items that tend to influ-ence residual compressive strength to be reported; theseinclude the following: material, methods of material fabrica-ti
47、on, accuracy of lay-up orientation, laminate stacking se-quence and overall thickness, specimen geometry, specimenpreparation, specimen conditioning, environment of testing,void content, volume percent reinforcement, type, size andlocation of damage (including method of non-destructiveinspection), s
48、pecimen/fixture alignment and gripping, andspeed 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-m
49、ent.6. Interferences6.1 The response of a damaged specimen is dependent uponmany factors, such as laminate thickness, ply thickness, stack-ing sequence, environment, damage type, damage geometry,FIG. 5 Support Fixture Angles (Inch-Pound Version)D 7137/D 7137M 05e15damage location, and loading/support conditions. Conse-quently, comparisons cannot be made between materials unlessidentical test configurations, test conditions, and laminateconfigurations are used. Therefore, all deviations from thestandard test configuration shall be reported in the res
