1、Designation: D7137/D7137M 12D7137/D7137M 17Standard 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 original adopt
2、ion 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 properties of multi
3、directional 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-fiberreinforced
4、 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 impacted plates
5、, 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 tolerance propertie
6、s 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 conditions. Thus,
7、 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 incidence o
8、f 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. The values stated in eachsyst
9、em may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from thetwo systems may result in non-conformance with the standard.1.5.1 Within the text the inch-pound units are shown in brackets.1.6 This standard does not purport to address all of
10、 the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety safety, health, and healthenvironmental practices and determine theapplicability of regulatory limitations prior to use.1.7 This international standard was deve
11、loped in accordance with internationally recognized principles on standardizationestablished in the Decision on Principles for the Development of International Standards, Guides and Recommendations issuedby the World Trade Organization Technical Barriers to Trade (TBT) Committee.2. Referenced Docume
12、nts2.1 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/D5229M Test Method for Moisture
13、 Absorption Properties and Equilibrium Conditioning of Polymer Matrix CompositeMaterials1 This test method is under the jurisdiction of ASTM Committee D30 on Composite Materials and is the direct responsibility of Subcommittee D30.05 on Structural TestMethods.Current edition approved April 1, 2012Oc
14、t. 15, 2017. Published May 2012.October 2017. Originally approved in 2005. Last previous edition approved in 20072012 asD7137/D7137M-07.-12. DOI: 10.1520/D7137_D7137M-12.10.1520/D7137_D7137M-17.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at se
15、rviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This 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
16、. Becauseit may not be technically 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,
17、 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1D5687/D5687M Guide for Preparation of Flat Composite Panels with Processing Guidelines for Specimen PreparationD6264/D6264M Test Method for Measuring the Damage Resistance of a Fiber-Reinforced Polymer-Matrix Compos
18、ite to aConcentrated Quasi-Static Indentation ForceD6641/D6641M Test Method for Compressive Properties of Polymer Matrix Composite Materials Using a Combined LoadingCompression (CLC) Test FixtureD7136/D7136M Test Method for Measuring the Damage Resistance of a Fiber-Reinforced Polymer Matrix Composi
19、te to aDrop-Weight Impact EventE4 Practices for Force Verification of Testing MachinesE6 Terminology Relating to Methods of Mechanical TestingE122 Practice for Calculating Sample Size to Estimate, With Specified Precision, the Average for a Characteristic of a Lot orProcessE177 Practice for Use of t
20、he Terms Precision and Bias in ASTM Test MethodsE456 Terminology Relating to Quality and StatisticsE1309 Guide for Identification of Fiber-Reinforced Polymer-Matrix Composite Materials in Databases (Withdrawn 2015)3E1434 Guide for Recording Mechanical Test Data of Fiber-Reinforced Composite Material
21、s in Databases (Withdrawn 2015)32.2 Military Standards:NASA 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 pla
22、stics.Terminology 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
23、 If the term 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,
24、 for thermodynamic 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
25、a measurable 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
26、.1 DiscussionCommon usage, at least for Cartesian axes (123,xyz, and so forth), generally assigns the coordinate system axes to the normaldirections of planes of symmetry in order that the highest property value in a normal direction (for elastic properties, the axis ofgreatest stiffness) would be 1
27、 or x, and the lowest (if applicable) would be 3 or z. Anisotropic materials do not have a principalmaterial coordinate system due to the total lack of symmetry, while, for isotropic materials, any coordinate system is a principalmaterial coordinate system. In laminated composites, the principal mat
28、erial coordinate system has meaning only with respect toan 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 c
29、oordinate 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
30、an orthotropic 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/90jns family as viewedfrom the reference coordinate system, such that the membrane-bending coupling terms of the lami
31、nate constitutive 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 diameterECAI = effective compressive modulus in the test directionFCAI = ultimate compressive residual stre
32、ngth in the test directionh = specimen thickness3 Available from National Aeronautics and Space Administration (NASA)-Langley Research Center, Hampton, VA 23681-2199.D7137/D7137M 172l = specimen lengthn = number of specimens per sample populationN = number of plies in laminate under testPmax = maxim
33、um force carried by test specimen prior to failureSn-1 = standard deviation 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
34、for a given property4. Summary of Test Method4.1 A uniaxial compression test 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 in
35、dentation or drop-weight impact.4.1.1 Quasi-Static IndentationThe rectangular plate is damaged due to application of an out-of-plane static indentation forcein accordance with Test Method D6264/D6264M.4.1.2 Drop-Weight ImpactThe rectangular plate is damaged due to application of an out-of-plane drop
36、-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 flat platens and end-loaded under compr
37、essive 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 instances when the damage produces a relativel
38、y 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 representative of a particular structural app
39、lication).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 of a laminated compositeplate is useful f
40、or 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 allowables, as the results are specific to th
41、egeometry 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 damagetolerance response upon the pre-existen
42、t 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 understood that thedamage tolerance of a composi
43、te 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 compressiveFIG. 1 Schematic of Compressive Residual Strength Support Fixture with Spec
44、imen in PlaceD7137/D7137M 173strength can result due to differences in these parameters. For example, residual strength and stiffness properties obtained usingFIG. 2 Support Fixture AssemblyFIG. 3 Support Fixture Base Plate (Inch-Pound Version)D7137/D7137M 174this test method would more likely refle
45、ct 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. Similarly, test specimen properties would be expectedto be similar to those of a panel with equivalent length and width dimensions, in
46、 comparison to those of a panel significantly largerthan the test specimen.5.4 The reporting section requires items that tend to influence residual compressive strength to be reported; these include thefollowing: material, methods of material fabrication, accuracy of lay-up orientation, laminate sta
47、cking sequence and overallthickness, specimen geometry, specimen preparation, specimen conditioning, environment of testing, void content, volume percentFIG. 4 Support Fixture Base Plate (SI Version)FIG. 5 Support Fixture Angles (Inch-Pound Version)D7137/D7137M 175FIG. 6 Support Fixture Angles (SI V
48、ersion)FIG. 7 Support Fixture Side Plates and Base Slideplates (Inch-Pound Version)D7137/D7137M 176reinforcement, 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
49、result from the residual strength assessment include the following: compressive residual strength FCAI,compressive force as a function of crosshead displacement, and surface strains as functions of crosshead displacement.6. Interferences6.1 The response of a damaged specimen is dependent upon many factors, such as laminate thickness, ply thickness, stackingsequence, environment, damage type, damage geometry, damage location, and loading/support conditions. Consequently,comparisons cannot be made between materials unless identical test configurations,
