1、Designation: D3878 07 (Reapproved 2013)D3878 15Standard Terminology forComposite Materials1This standard is issued under the fixed designation D3878; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A numb
2、er in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the U.S. Department of Defense.1. Scope1.1 These definitions cover generic terms, including term
3、s of commercial importance, that appear in one or more standards oncomposites containing high-modulus (greater than 20-GPa (3 106 psi) fibers.1.2 The definitions cover, in most cases, special meanings used in the composites industry. No attempt has been made to includecommon meanings of the same ter
4、ms as used outside the composites industry.1.3 Definitions included have, in general, been approved as standard.2. Referenced Documents2.1 ASTM Standards:2D123 Terminology Relating to Textiles2.2 MilitaryIndustry Standard:3MIL-HDBK-17CMH-17 Composite Materials Handbook3. Terminology3.1 Definitions:6
5、45 laminatea balanced symmetric laminate composed of only +45 plies and 45 plies.angleply laminateany balanced laminate consisting of plus and minus theta plies where theta is an acute angle with respect toa reference direction.balanced laminateany laminate that contains one ply of minus theta orien
6、tation with respect to the laminate principal axis forevery identical ply with a plus theta orientation.bond, nthe act of adhering one surface to another, with or without the use of an adhesive at the interface.secondary bond, nthe act of bonding two or more already-cured composite or other solid ma
7、terials, during which the onlychemical or thermal reaction, or both, occurring is the curing of the adhesive itself.DISCUSSIONFor example, a previously cured composite or metal doubler bonded via an adhesive to a previously cured skin, or a previously cured face sheet bondedvia an adhesive to a hone
8、ycomb core. Also applies to bonding metallic substrates such as aluminum face sheets onto aluminum honeycomb core.braided fabricsee braided fabric under fabric.breather string, na string, composed of a material such as glass, that provides a vacuum path from the laminate to a breather.bundlea genera
9、l term for a collection of essentially parallel filaments.1 This terminology is under the jurisdiction of ASTM Committee D30 on Composite Materials and is the direct responsibility of Subcommittee D30.01 on Editorial andResource Standards.Current edition approved May 1, 2013July 1, 2015. Published M
10、ay 2013August 2015. Originally approved in 1981. Last previous edition approved in 20072013 asD3878 07.D3878 07(2013). DOI: 10.1520/D3878-07R13.10.1520/D3878-15.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. ForAnnual Book ofA
11、STM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.3 Available fromASTMSAE International as(SAE), The Composite Materials HandbookMIL17.400 Commonwealth Dr., Warrendale,Also available as MIL-HDBK-17from Standardization Documents Order Desk, DODSSP, Bldg
12、. 4, Section D, 700 Robbins Ave., Philadelphia, PA 19111-5094PA 15096, http:/www.sae.org.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. Becauseit may not be technically possible
13、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 C700, West Co
14、nshohocken, PA 19428-2959. United States1carbon fiber precursora material from which carbon fiber is made by pyrolysis. Polyacrylonitrile, rayon, or pitch fibers arecommonly used precursors.catenary:filament catenarythe difference in length of the filaments in a specified length of tow, end, or stra
15、nd as a result of unequaltension; the tendency of some filaments in a taut horizontal tow, end, or strand to sag lower than others.roving catenarythe difference in length of the ends, tows, or strands in a specified length of roving as a result of unequaltension; the tendency of some ends, tows, or
16、strands in a taut horizontal roving to sag lower than others.caul, na flat or contoured tool used to distribute pressure and to define a surface for the top of the laminate during laminateconsolidation or cure.co-bond, n(cobond) the act of bonding one semi-solid media (e.g. uncured thermoset polymer
17、 or a thermoplastic polymer) toa solid in a single process through principal action of the matrix possibly with the inclusion of a separate layer of adhesive.co-cure, n(cocure) the act of curing two semi-solid media (i.e. uncured thermoset polymers) in a single process resulting in thetwo media bein
18、g bonded through principal action of the matrix, possibly with the inclusion of a separate layer of adhesive atthe interface.co-fabrication, n(in sandwich constructions,cofabrication) a fabrication process where items such as inserts and other structuraldetails are bonded into the panel a composite
19、structural component at the same time that the facings are bonded to ponent is cured or posite:composite materiala substance consisting of two or more materials, insoluble in one another, which are combined to form auseful engineering material possessing certain properties not possessed by the const
20、ituents.DISCUSSIONa composite material is inherently inhomogeneous on a microscopic scale but can often be assumed to be homogeneous on a macroscopic scale forcertain engineering applications. The constituents of a composite retain their identities: they do not dissolve or otherwise merge completely
21、 into eachother, although they act in concert.discontinuous fiber-reinforced composite any composite material consisting of a matrix reinforced by discontinuous fibers.The fibers may be whiskers or chopped fibers.fabric-reinforced compositeany composite material consisting of a matrix reinforced by
22、fabric (woven, knitted, or braidedassemblages of fibers).fiber-reinforced compositeany composite material consisting of a matrix reinforced by continuous or discontinuous fibers.filamentary compositea composite material reinforced with continuous fibers.unidirectional fiber-reinforced compositeany f
23、iber-reinforced composite with all fibers aligned in a single direction.continuous filament yarn, ntwo or more continuous filaments twisted into a single fiber bundle.core, nan inner layer of a multi-layer adherend assembly.DISCUSSIONThe core is usually of a relatively low density material. It separ
24、ates the surface layers, and other possible layers, of a multi-layer construction, generallystabilizing and transmitting shear between them.honeycomb core, na core material having a thin-walled cell structure (often hexagonal) formed from a sheet material andresembling natural honeycomb in appearanc
25、e.DISCUSSIONHoneycomb core materials exhibit anisotropic behavior; therefore the following notation is used:L = ribbon or longitudinal direction of core, parallel to the material used to construct the core;W = expanded or transverse direction of core; andT = core thickness or cell depth.core shear i
26、nstability, nthe buckling of the core due to transverse shear stresses.DISCUSSIOND3878 152Core shear instability is transverse-shear stress-induced, occurs through the depth (thickness) of the core, and may result in failure of the componentby causing the face sheets to also fail locally due to redu
27、ction in support. This phenomenon is sometimes imprecisely referred to as “shear crimping.”crossply laminatea laminate composed of only 0 and 90 plies. This is not necessarily symmetric.cure, nin thermoset polymer composite materials, the process resulting in the overall transformation of the polyme
28、ric matrixphase of the composite from a low molecular weight resin/hardener system to a cross-linked network by chemical reactiondam, na solid material (such as silicone rubber, steel, or aluminum), used in processing composites, to contain the matrixmaterial within defined boundaries or to prevent
29、crowning of a processing bag.damage, nin structures and structural mechanics, a structural anomaly in material or structure created by manufacturing orservice usage.damage resistance, n in structures and structural mechanics, a measure of the relationship between the force, energy, or otherparameter
30、(s) associated with an event or sequence of events and the resulting damage size and type.DISCUSSIONDamage resistance increases as the force, energy, or other parameter increases for a given size or type of damage. Conversely, damage resistanceincreases as damage decreases, for a given applied force
31、, energy, or other parameter. Damage resistance and damage tolerance are often confused. Amaterial or structure with high damage resistance will incur less physical damage from a given event. Materials or structures with high damagetolerance may incur varying levels of physical damage but will have
32、high amounts of remaining functionality.Adamage-resistant material or structuremay, or may not, be considered damage tolerant.damage tolerance, n1) in structures and structure materials, a measure of the relationship between damage size and type andthe level of a performance parameter, such as stiff
33、ness or strength, at which the structure or structural material can operate fora particular loading condition; 2) in structural systems, a measure of the ability of such systems to function at designatedperformance parameters (for example, magnitude, length of time, and type of loading(s) without sy
34、stem failure in the presenceof a particular or specified level of damage.DISCUSSIONDamage tolerance involves, and can be provided by, a number of factors operating at a number of levels: structural material, structural, and overallsystem. These factors include 1) basic material ability to operate wi
35、th damage present (often referred to as the residual strength aspect), 2) damagegrowth resistance and containment provided by material and structural considerations, and 3) system inspection and maintenance plans which allowthe damage to be detected and corrected and which depend upon material, stru
36、ctural, and operational considerations.Damage tolerance increases as the damage size increases for a given level of a performance parameter. Damage tolerance increases as the level ofthe performance parameter increases for a given damage size. Damage tolerance depends upon the type of loading which
37、is applied. For example, thedamage tolerance for a compressive load can be, and generally is, different than for the same level of tensile load.Damage resistance is often confused with damage tolerance. Damage tolerance is directly related only to the size and type of damage while beingonly indirect
38、ly related to how the damage was created (see damage resistance). Thus, damage tolerance is distinct from damage resistance.debonda deliberate separation of a bonded joint or interface, usually for repair or rework purposes.debulk, vto decrease voids between lamina before laminate consolidation thro
39、ugh use of vacuum or by mechanical means.DISCUSSIONLaminae can be debulked at ambient or elevated temperatures.delaminationseparation of plies in a laminate. This may be local or may cover a large area in the laminate.denier, na direct numbering system for expressing linear density, equal to the mas
40、s in grams per 9000 metres of yarn, filament,fiber, or other textile strand.disbondan area within a bonded interface between two adherents in which an adhesive or cohesive failure has occurred. It mayoccur at any time during the life of the structure and may arise from a wide variety of causes. It i
41、s sometimes used to describean area of separation between two laminae in the finished laminate (the term “delamination” is preferred).discontinuous fibera polycrystalline or amorphous fiber that is discontinuous within the sample or component or that has oneor both ends inside of the stress field un
42、der consideration. The minimum diameter of a discontinuous fiber is not limited, butthe maximum diameter may not exceed 0.25 mm (0.010 in.).end, nin fibrous composites, a general term for a continuous, ordered assembly of essentially parallel, collimated filaments, withor without twist.D3878 153DISC
43、USSIONThis term covers tow, strand, sliver, yarn, and roving. The relationship between fiber form terms is shown in Table X1.1.fabrica planar textile (Synonym: cdth)braided fabric, na cloth constructed by a braiding process.knitted fabric, na cloth constructed by a knitting process.nonwoven fabric,
44、na cloth constructed by bonding or interlocking, or both (but not interlacing) fiber by any combination ofmechanical, chemical, thermal, or solvent means.plied yarn, na yarn formed by twisting together two or more single yarns in one operation.DISCUSSIONPlying, which is done in the opposite directio
45、n from the twist of each of the simple yarns, serves to counter the tendency of simple yarns to untwist.woven fabric, na cloth constructed by a weaving process.face sheets, n(facesheets) in sandwich construction, the outer structural layers on each face of the core. (Synonyms: face, skin,facing.)DIS
46、CUSSIONThe face sheets are generally thin and of higher density relative to the core. The face sheets provide the primary ability to equilibrate the in-planenormal and shear forces from bending and torsion applied to the construction. If the face sheets are composite, then the entire composite lamin
47、atebonded to one side of the core constitutes a face sheet.face sheet dimpling, nin sandwich construction,(1) the buckling of a face sheet into or out of the individual cells of ahoneycomb core due to localized compressive or shear stresses, or both, or (2) the sagging of the face sheet into the ind
48、ividualhoneycomb cells during curing of composite face sheets onto the core.DISCUSSIONAlthough described by the same phrase, these two phenomena are different in nature and in subsequent effects.fabrication, nthe process of manufacturing, forming, constructing, or assembling a product or component.f
49、iber, none or more filaments in an ordered assemblage.DISCUSSIONThere are a number of general and specific terms that define specific types of fiber forms. The relationship between fiber form terms is shown in Table1.fiber contentthe amount of fiber present in a composite expressed either as percent by weight or percent by volume. This issometimes stated as a fraction, that is, fiber volume fraction.fiber volume fractionsee fiber content.filament, na fibrous form of matter wit
