1、Designation:D7137/D7137M07 Designation: D7137/D7137M 12Standard Test Method forCompressive Residual Strength Properties of DamagedPolymer Matrix Composite Plates1This standard is issued under the fixed designation D7137/D7137M; the number immediately following the designation indicates theyear of or
2、iginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of lastreapproval. A superscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers compression residual strength propert
3、ies of multidirectional polymer matrix composite laminatedplates, which have been subjected to quasi-static indentation per Test Method D6264/D6264M or drop-weight impact per TestMethod D7136/D7136M prior to application of compressive force. The composite material forms are limited to continuous-fib
4、erreinforced polymer matrix composites with multidirectional fiber orientations, and which are both symmetric and balanced withrespect to the test direction. The range of acceptable test laminates and thicknesses is defined in 8.2.NOTE 1When used to determine the residual strength of drop-weight imp
5、acted plates, this test method is commonly referred to as the CompressionAfter Impact, or CAI, method.1.2 The method utilizes a flat, rectangular composite plate, previously subjected to a damaging event, which is tested undercompressive loading using a stabilization fixture.NOTE 2The damage toleran
6、ce properties obtained are particular to the type, geometry and location of damage inflicted upon the plate.1.3 The properties generated by this test method are highly dependent upon several factors, which include specimen geometry,layup, damage type, damage size, damage location, and boundary condi
7、tions. Thus, results are generally not scalable to otherconfigurations, and are particular to the combination of geometric and physical conditions tested.1.4 This test method can be used to test undamaged polymer matrix composite plates, but historically such tests havedemonstrated a relatively high
8、 incidence of undesirable failure modes (such as end crushing). Test Method D6641/D6641M isrecommended for obtaining compressive properties of undamaged polymer matrix composites.1.5 The values stated in either SI units or inch-pound units are to be regarded separately as standard. Within the text t
9、heinch-pound units are shown in brackets. The values stated in each system aremay not be exact equivalents; therefore, each systemmustshall be used independently of the other. Combining values from the two systems may result in non-conformance with thestandard.1.5.1 Within the text the inch-pound un
10、its are shown in brackets.1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prio
11、r to use.2. Referenced Documents2.1 ASTM Standards:2D792 Test Methods for Density and Specific Gravity (Relative Density) of Plastics by DisplacementD883 Terminology Relating to PlasticsD3171 Test Methods for Constituent Content of Composite MaterialsD3878 Terminology for Composite MaterialsD5229/D5
12、229M Test Method for Moisture Absorption Properties and Equilibrium Conditioning of Polymer Matrix CompositeMaterialsD5687/D5687M Guide for Preparation of Flat Composite Panels with Processing Guidelines for Specimen Preparation1This test method is under the jurisdiction of ASTM Committee D30 on Com
13、posite Materials and is the direct responsibility of Subcommittee D30.05 on Structural TestMethods.Current edition approved Nov. 15, 2007. Published December 2007. Originally approved in 2005. Last previous edition approved in 2005 as D7137/D7137M-051. DOI:10.1520/D7137_D7137M-07.Current edition app
14、roved April 1, 2012. Published May 2012. Originally approved in 2005. Last previous edition approved in 2007 as D7137/D7137M-07. DOI:10.1520/D7137_D7137M-12.2For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at serviceastm.org. For Annual Book of A
15、STM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.1This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically
16、 possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C70
17、0, West Conshohocken, PA 19428-2959, United States.D6264/D6264M Test Method for Measuring the Damage Resistance of a Fiber-Reinforced Polymer-Matrix Composite to aConcentrated Quasi-Static Indentation ForceD6641/D6641M Test Method for Compressive Properties of Polymer Matrix Composite Materials Usin
18、g a Combined LoadingCompression (CLC) Test FixtureD7136/D7136M Test Method for Measuring the Damage Resistance of a Fiber-Reinforced Polymer Matrix Composite to aDrop-Weight Impact EventE4 Practices for Force Verification of Testing MachinesE6 Terminology Relating to Methods of Mechanical TestingE12
19、2 Practice for Calculating Sample Size to Estimate, With Specified Precision, the Average for a Characteristic of a Lot orProcessE177 Practice for Use of the Terms Precision and Bias in ASTM Test MethodsE456 Terminology Relating to Quality and StatisticsE1309 Guide for Identification of Fiber-Reinfo
20、rced Polymer-Matrix Composite Materials in DatabasesE1434 Guide for Recording Mechanical Test Data of Fiber-Reinforced Composite Materials in Databases2.2 Military Standards:MIL-HDBK-17-3F Composite Materials Handbook, Volume 3Polymer Matrix Composites Materials Usage, Design andAnalysisMIL-HDBK-728
21、/1Nondestructive TestingMIL-HDBK-731ANondestructive Testing Methods of Composite MaterialsThermography4MIL-HDBK-732A Nondestructive Testing Methods of Composite MaterialsAcoustic Emission4MIL-HDBK-733ANondestructive Testing Methods of Composite MaterialsRadiography4MIL-HDBK-787ANondestructive Testin
22、g Methods of Composite MaterialsUltrasonics4NASA Reference Publication 1092 Standard Tests for Toughened Resin Composites, Revised Edition, July 198333. Terminology3.1 DefinitionsTerminology D3878 defines terms relating to composite materials. Terminology D883 defines terms relatingto plastics. Term
23、inology E6 defines terms relating to mechanical testing. Terminology E456 and Practice E177 define terms relatingto statistics. In the event of a conflict between terms, Terminology D3878 shall have precedence over the other standards.3.2 Definitions of Terms Specific to This Standard:3.2.1 If the t
24、erm represents a physical quantity, its analytical dimensions are stated immediately following the term (or lettersymbol) in fundamental dimension form, using the following ASTM standard symbology for fundamental dimensions, shownwithin square brackets: M for mass, L for length, T for time, u for th
25、ermodynamic temperature, and nd for non-dimensionalquantities. Use of these symbols is restricted to analytical dimensions when used with square brackets, as the symbols may haveother definitions when used without the brackets.3.2.2 nominal value, na value, existing in name only, assigned to a measu
26、rable property for the purpose of convenientdesignation. Tolerances may be applied to a nominal value to define an acceptable range for the property.3.2.3 principal material coordinate system, na coordinate system with axes that are normal to the planes of symmetry inherentto a material.3.2.3.1 Disc
27、ussionCommon usage, at least for Cartesian axes (123, xyz, and so forth), generally assigns the coordinate systemaxes to the normal directions of planes of symmetry in order that the highest property value in a normal direction (for elasticproperties, the axis of greatest stiffness) would be 1 or x,
28、 and the lowest (if applicable) would be 3 or z. Anisotropic materials donot have a principal material coordinate system due to the total lack of symmetry, while, for isotropic materials, any coordinatesystem is a principal material coordinate system. In laminated composites, the principal material
29、coordinate system has meaningonly with respect to an individual orthotropic lamina. The related term for laminated composites is “reference coordinate system.”3.2.4 reference coordinate system, na coordinate system for laminated composites used to define ply orientations. One of thereference coordin
30、ate system axes (normally the Cartesian x-axis) is designated the reference axis, assigned a position, and the plyprincipal axis of each ply in the laminate is referenced relative to the reference axis to define the ply orientation for that ply.3.2.5 specially orthotropic, adja description of an ort
31、hotropic material as viewed in its principal material coordinate system.In laminated composites, a specially orthotropic laminate is a balanced and symmetric laminate of the 0i/90jnsfamily as viewedfrom the reference coordinate system, such that the membrane-bending coupling terms of the laminate co
32、nstitutive relation arezero.3.3 Symbols:A = cross-sectional area of a specimenCV = coefficient of variation statistic of a sample population for a given property (in percent)D = damage diameter3Available from U.S. Army Research Laboratory, Materials Directorate, Aberdeen Proving Ground, MD 21001.3Av
33、ailable from National Aeronautics and Space Administration (NASA)-Langley Research Center, Hampton, VA 23681-2199.D7137/D7137M 122ECAI= effective compressive modulus in the test directionFCAI= ultimate compressive residual strength in the test directionFIG. 1 Schematic of Compressive Residual Streng
34、th Support Fixture with Specimen in PlaceFIG. 2 Support Fixture AssemblyD7137/D7137M 123h = specimen thicknessl = specimen lengthn = number of specimens per sample populationN = number of plies in laminate under testPmax= maximum force carried by test specimen prior to failureSn-1= standard deviatio
35、n statistic of a sample population for a given propertyw = specimen widthxi= test result for an individual specimen from the sample population for a given propertyx= mean or average (estimate of mean) of a sample population for a given property4. Summary of Test Method4.1 A uniaxial compression test
36、 is performed using a balanced, symmetric laminated plate, which has been damaged andinspected prior to the application of compressive force. The damage state is imparted through out-of-plane loading caused byquasi-static indentation or drop-weight impact.4.1.1 Quasi-Static IndentationThe rectangula
37、r plate is damaged due to application of an out-of-plane static indentation forcein accordance with Test Method D6264/D6264M.FIG. 3 Support Fixture Base Plate (Inch-Pound Version)FIG. 4 Support Fixture Base Plate (SI Version)D7137/D7137M 1244.1.2 Drop-Weight ImpactThe rectangular plate is damaged du
38、e to application of an out-of-plane drop-weight impact inaccordance with Test Method D7136/D7136M.4.2 The damaged plate is installed in a multi-piece support fixture, that has been aligned to minimize loading eccentricities andinduced specimen bending. The specimen/fixture assembly is placed between
39、 flat platens and end-loaded under compressive forceuntil failure. Applied force, crosshead displacement, and strain data are recorded while loading.4.3 Preferred failure modes pass through the damage in the test specimen. However, acceptable failures may initiate away fromthe damage site, in instan
40、ces when the damage produces a relatively low stress concentration or if the extent of damage is small,or both. Unacceptable failure modes are those related to load introduction by the support fixture, local edge support conditions,and specimen instability (unless the specimen is dimensionally repre
41、sentative of a particular structural application).5. Significance and Use5.1 Susceptibility to damage from concentrated out-of-plane forces is one of the major design concerns of many structures madeof advanced composite laminates. Knowledge of the damage resistance and damage tolerance properties o
42、f a laminated compositeplate is useful for product development and material selection.5.2 The residual strength data obtained using this test method is most commonly used in material specifications and researchand development activities. The data are not intended for use in establishing design allow
43、ables, as the results are specific to thegeometry and physical conditions tested and are generally not scalable to other configurations. Its usefulness in establishing qualityassurance requirements is also limited, due to the inherent variability of induced damage, as well as the dependency of damag
44、etolerance response upon the pre-existent damage state.5.3 The properties obtained using this test method can provide guidance in regard to the anticipated damage tolerance capabilityof composite structures of similar material, thickness, stacking sequence, and so forth. However, it must be understo
45、od that thedamage tolerance of a composite structure is highly dependent upon several factors including geometry, stiffness, supportconditions, and so forth. Significant differences in the relationships between the existent damage state and the residual compressivestrength can result due to differen
46、ces in these parameters. For example, residual strength and stiffness properties obtained usingthis test method would more likely reflect the damage tolerance characteristics of an un-stiffened monolithic skin or web than thatof a skin attached to substructure which resists out-of-plane deformation.
47、 Similarly, test specimen properties would be expectedto be similar to those of a panel with equivalent length and width dimensions, in comparison to those of a panel significantly largerthan the test specimen.5.4 The reporting section requires items that tend to influence residual compressive stren
48、gth to be reported; these include theFIG. 5 Support Fixture Angles (Inch-Pound Version)D7137/D7137M 125FIG. 6 Support Fixture Angles (SI Version)FIG. 7 Support Fixture Side Plates and Base Slideplates (Inch-Pound Version)D7137/D7137M 126following: material, methods of material fabrication, accuracy
49、of lay-up orientation, laminate stacking sequence and overallthickness, specimen geometry, specimen preparation, specimen conditioning, environment of testing, void content, volume percentreinforcement, type, size and location of damage (including method of non-destructive inspection), specimen/fixture alignment andgripping, time at temperature, and speed of testing.5.5 Properties that result from the residual strength assessment include the following: compressive residual strength FCAI,compressive force as a function of crosshead displacement, an
