1、Designation:D7136/D7136M07 Designation: D7136/D7136M 12Standard Test Method forMeasuring the Damage Resistance of a Fiber-ReinforcedPolymer Matrix Composite to a Drop-Weight Impact Event1This standard is issued under the fixed designation D7136/D7136M; the number immediately following the designatio
2、n indicates theyear of original 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 determines the dama
3、ge resistance of multidirectional polymer matrix composite laminated plates subjectedto a drop-weight impact event. The composite material forms are limited to continuous-fiber reinforced polymer matrixcomposites, with the range of acceptable test laminates and thicknesses defined in 8.2.1.1.1 Instr
4、uctions for modifying these procedures to determine damage resistance properties of sandwich constructions areprovided in Practice D7766/D7766M.1.2 A flat, rectangular composite plate is subjected to an out-of-plane, concentrated impact using a drop-weight device with ahemispherical impactor. The po
5、tential energy of the drop-weight, as defined by the mass and drop height of the impactor, isspecified prior to test. Equipment and procedures are provided for optional measurement of contact force and velocity during theimpact event. The damage resistance is quantified in terms of the resulting siz
6、e and type of damage in the specimen.1.3 The test method may be used to screen materials for damage resistance, or to inflict damage into a specimen for subsequentdamage tolerance testing. When the impacted plate is tested in accordance with Test Method D7137/D7137M, the overall testsequence is comm
7、only referred to as the CompressionAfter Impact (CAI) method. Quasi-static indentation per Test Method D6264D6264/D6264M may be used as an alternate method of creating damage from an out-of-plane force and measuring damageresistance properties.1.4 The damage resistance properties generated by this t
8、est method are highly dependent upon several factors, which includespecimen geometry, layup, impactor geometry, impactor mass, impact force, impact energy, and boundary conditions. Thus, resultsare generally not scalable to other configurations, and are particular to the combination of geometric and
9、 physical conditions tested.1.5 The values stated in either SI units or inch-pound units are to be regarded separately as standard. Within the text theinch-pound units are shown in brackets. The values stated in each system aremay not be exact equivalents; therefore, each systemmustshall be used ind
10、ependently 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 units 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 responsi
11、bilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D792 Test Methods for Density and Specific Gravity (Relative Density) of Plastics by DisplacementD8
12、83 Terminology Relating to PlasticsD3771 Specification for Rubber Seals Used in Concentrating Solar CollectorsD3763 Test Method for High Speed Puncture Properties of Plastics Using Load and Displacement SensorsD3878 Terminology for Composite MaterialsD5229/D5229M Test Method for Moisture Absorption
13、Properties and Equilibrium Conditioning of Polymer Matrix CompositeMaterialsD5678 Test Method for Freeze/Thaw Resistance of Wax Emulsion Floor Polish1This test method is under the jurisdiction of ASTM Committee D30 on Composite Materials and is the direct responsibility of Subcommittee D30.05 on Str
14、uctural TestMethods.Current edition approved Oct. 1, 2007. Published November 2007. Originally approved in 2005. Last previous edition approved in 2005 as D7136/D7136M-051. DOI:10.1520/D7136_D7136M-07.Current edition approved April 1, 2012. Published May 2012. Originally approved in 2005. Last previ
15、ous edition approved in 2007 as D7136/D7136M - 07. DOI:10.1520/D7136_D7136M-12.2For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page
16、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 possible to adequately depict all changes accurately, ASTM recommends that us
17、ers 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 C700, West Conshohocken, PA 19428-2959, United States.D6264/D6264M Test Method fo
18、r Measuring the Damage Resistance of a Fiber-Reinforced Polymer-Matrix Composite to aConcentrated Quasi-Static Indentation ForceD7137/D7137M Test Method for Compressive Residual Strength Properties of Damaged Polymer Matrix Composite PlatesD7766/D7766M Practice for Damage Resistance Testing of Sandw
19、ich ConstructionsE4 Practices for Force Verification of Testing MachinesE6 Terminology Relating to Methods of Mechanical TestingE18 Test Methods for Rockwell Hardness of Metallic MaterialsE122 Practice for Calculating Sample Size to Estimate, With Specified Precision, the Average for a Characteristi
20、c 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-Reinforced Polymer-Matrix Composite Materials in DatabasesE1434 Guide for Recording Mechanical Test Data of Fiber-R
21、einforced Composite Materials in Databases Guide for RecordingMechanical Test Data of Fiber-Reinforced Composite Materials in DatabasesE2533 Guide for Nondestructive Testing of Polymer Matrix Composites Used in Aerospace Applications2.2 Military Standards:MIL-HDBK-17-3F Composite Materials Handbook,
22、 Volume 3Polymer Matrix Composites Materials Usage, Design andAnalysis3MIL-HDBK-728/1 Nondestructive Testing4MIL-HDBK-731A Nondestructive Testing Methods of Composite MaterialsThermography4MIL-HDBK-732A Nondestructive Testing Methods of Composite MaterialsAcoustic Emission4MIL-HDBK-733A Nondestructi
23、ve Testing Methods of Composite MaterialsRadiography4MIL-HDBK-787A Nondestructive Testing Methods of Composite MaterialsUltrasonics4NASA Reference Publication 1092 Standard Tests for Toughened Resin Composites, Revised Edition, July 198353. Terminology3.1 DefinitionsTerminology D3878 defines terms r
24、elating to composite materials. Terminology D883 defines terms relatingto plastics. 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 ov
25、er the other standards.3.2 Definitions of Terms Specific to This Standard:3.2.1 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
26、 dimensions, shownwithin square brackets: M for mass, L for length, T for time, u 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 withou
27、t the brackets.3.2.2 dent depth, d L, nresidual depth of the depression formed by an impactor after the impact event. The dent depth shallbe defined as the maximum distance in a direction normal to the face of the specimen from the lowest point in the dent to the planeof the impacted surface that is
28、 undisturbed by the dent.3.2.3 nominal value, na value, existing in name only, assigned to a measurable property for the purpose of convenientdesignation. Tolerances may be applied to a nominal value to define an acceptable range for the property.3.2.4 principal material coordinate system, na coordi
29、nate system with axes that are normal to the planes of symmetry inherentto a material.3.2.4.1 DiscussionCommon 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 va
30、lue in a normal direction (for elasticproperties, the axis of greatest stiffness) would be 1 or x, 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 coordinate
31、system is a principal material coordinate system. In laminated composites, the principal material coordinate system has meaningonly with respect to an individual orthotropic lamina. The related term for laminated composites is “reference coordinate system.”3.2.5 recorded contact force, F MLT-2, nthe
32、 force exerted by the impactor on the specimen during the impact event, asrecorded by a force indicator.3.2.6 reference coordinate system, na coordinate system for laminated composites used to define ply orientations. One of thereference coordinate system axes (normally the Cartesian x-axis) is desi
33、gnated 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.3.2.7 striker tip, nthe portion or component of the impactor which comes into contact with the test specimen f
34、irst during theimpact event.3Available from U.S. Army Research Laboratory, Materials Directorate, Aberdeen Proving Ground, MD 21001.4Available from U.S. Army Materials Technology Laboratory, Watertown, MA 02471.5Available from National Aeronautics and Space Administration (NASA)-Langley Research Cen
35、ter, Hampton, VA 23681-2199.D7136/D7136M 1223.3 Symbols:A = cross-sectional area of a specimenCE= specified ratio of impact energy to specimen thicknessCV = coefficient of variation statistic of a sample population for a given property (in percent)D = damage diameter (see Fig. 11)d = dent depthE = p
36、otential energy of impactor prior to dropE1= absorbed energy at the time at which force versus time curve has a discontinuity in force or slopeEa= energy absorbed by the specimen during the impact eventEi= actual impact energy (incident kinetic energy)Emax= absorbed energy at the time of maximum rec
37、orded contact forceF = recorded contact forceF1= recorded contact force at which the force versus time curve has a discontinuity in force or slopeFmax= maximum recorded contact forceg = acceleration due to gravityh = specimen thicknessH = impactor drop heightl = specimen lengthm = impactor massmd= i
38、mpactor mass for drop height calculationmdlbm= impactor mass in standard gravity for drop height calculationn = number of specimens per sample populationN = number of plies in laminate under testSn-1= standard deviation statistic of a sample population for a given propertyt = time during impactor dr
39、op and impact eventti= time of initial contacttT= contact duration (total duration of the impact event)w = specimen widthv = impactor velocityvi= impactor velocity at time of initial contact, tiW12= distance between leading edges of the two flag prongs on velocity indicatorxi= test result for an ind
40、ividual specimen from the sample population for a given propertyx= mean or average (estimate of mean) of a sample population for a given propertyd = impactor displacement4. Summary of Test Method4.1 A drop-weight impact test is performed using a balanced, symmetric laminated plate. Damage is imparte
41、d throughout-of-plane, concentrated impact (perpendicular to the plane of the laminated plate) using a drop weight with a hemisphericalNOTEClamp tip centered 0.25 in. from edge of cut-out.FIG. 1 Impact Support Fixture (Inch-Pound Version)D7136/D7136M 123striker tip. The damage resistance is quantifi
42、ed in terms of the resulting size and type of damage in the specimen. The damageresponse is a function of the test configuration; comparisons cannot be made between materials unless identical test configurations,test conditions, and so forth are used.4.2 Optional procedures for recording impact velo
43、city and applied contact force versus time history data are provided.4.3 Preferred damage states resulting from the impact are located in the center of the plate, sufficiently far from the plate edgessuch that the local states of stress at the edges and at the impact location do not interact during
44、the damage formation event.5. Significance and Use5.1 Susceptibility to damage from concentrated out-of-plane impact forces is one of the major design concerns of manystructures made of advanced composite laminates. Knowledge of the damage resistance properties of a laminated composite plateis usefu
45、l for product development and material selection.5.2 Drop-weight impact testing can serve the following purposes:5.2.1 To establish quantitatively the effects of stacking sequence, fiber surface treatment, variations in fiber volume fraction, andprocessing and environmental variables on the damage r
46、esistance of a particular composite laminate to a concentrated drop-weightimpact force or energy.NOTEClamp tip centered 6 mm from edge of cut-out.FIG. 2 Impact Support Fixture (SI Version)FIG. 3 Representative Rigid Base (Inch-Pound Version)D7136/D7136M 1245.2.2 To compare quantitatively the relativ
47、e values of the damage resistance parameters for composite materials with differentconstituents. The damage response parameters can include dent depth, damage dimensions, and through-thickness locations, F1,Fmax, E1and Emax, as well as the force versus time curve.5.2.3 To impart damage in a specimen
48、 for subsequent damage tolerance tests, such as Test Method D7137/D7137M.5.3 The properties obtained using this test method can provide guidance in regard to the anticipated damage resistance capabilityof composite structures of similar material, thickness, stacking sequence, and so forth. However,
49、it must be understood that thedamage resistance of a composite structure is highly dependent upon several factors including geometry, thickness, stiffness, mass,FIG. 4 Representative Rigid Base (SI Version)FIG. 5 Impact Device with Cylindrical Tube Impactor Guide MechanismD7136/D7136M 125support conditions, and so forth. Significant differences in the relationships between impact force/energy and the resultant damagestate can result due to differences in these parameters. For example, properties obtained using this test method would more likelyref
