1、Designation: D 3878 07Standard Terminology forComposite Materials1This standard is issued under the fixed designation D 3878; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses indica
2、tes the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1. Scope1.1 These definitions cover generic terms, including termsof commercial importance, t
3、hat appear in one or more stan-dards on composites containing high-modulus (greater than20-GPa (3 3 106psi) fibers.1.2 The definitions cover, in most cases, special meaningsused in the composites industry. No attempt has been made toinclude common meanings of the same terms as used outsidethe compos
4、ites industry.1.3 Definitions included have, in general, been approved asstandard.2. Referenced Documents2.1 ASTM Standards:2D 123 Terminology Relating to Textiles2.2 Military Standard:MIL-HDBK-1733. Terminology3.1 Definitions:645 laminatea balanced symmetric laminate composed ofonly +45 plies and 4
5、5 plies.angleply laminateany balanced laminate consisting of plusand minus theta plies where theta is an acute angle withrespect to a reference direction.balanced laminateany laminate that contains one ply ofminus theta orientation with respect to the laminate principalaxis for every identical ply w
6、ith a plus theta orientation.braided fabricsee braided fabric under fabric.breather string, na string, composed of a material such asglass, that provides a vacuum path from the laminate to abreather.bundlea general term for a collection of essentially parallelfilaments.carbon fiber precursora materi
7、al from which carbon fiberis made by pyrolysis. Polyacrylonitrile, rayon, or pitch fibersare commonly used precursors.catenary:filament catenarythe difference in length of the filamentsin a specified length of tow, end, or strand as a result ofunequal tension; the tendency of some filaments in a tau
8、thorizontal 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 ofunequal tension; the tendency of some ends, tows, or strandsin a taut horizontal roving to sag lower than others.caul, na flat o
9、r contoured tool used to distribute pressure andto define a surface for the top of the laminate during laminateconsolidation or cure.co-fabrication, nin sandwich constructions, a fabricationprocess where items such as inserts and other structuraldetails are bonded into the panel at the same time tha
10、t thefacings are bonded to the posite:composite materiala substance consisting of two or morematerials, insoluble in one another, which are combined toform a useful engineering material possessing certain prop-erties not possessed by the constituents.DISCUSSIONa composite material is inherently inho
11、mogeneous on amicroscopic scale but can often be assumed to be homogeneous on amacroscopic scale for certain engineering applications. The constitu-ents of a composite retain their identities: they do not dissolve orotherwise merge completely into each other, although they act inconcert.discontinuou
12、s fiber-reinforced compositeany compositematerial consisting of a matrix reinforced by discontinuousfibers. The fibers may be whiskers or chopped fibers.fabric-reinforced compositeany composite material con-sisting of a matrix reinforced by fabric (woven, knitted, orbraided assemblages of fibers).1T
13、his terminology is under the jurisdiction of ASTM Committee D30 onComposite Materials and is the direct responsibility of Subcommittee D30.01 onEditorial and Resource Standards.Current edition approved May 1, 2007. Published June 2007. Originallyapproved in 1981. Last previous edition approved in 20
14、04 as D 3878 04a.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 onthe ASTM website.3Available from ASTM International as The Co
15、mposite Materials HandbookMIL 17. Also available as MIL-HDBK-17 from Standardization Documents OrderDesk, DODSSP, Bldg. 4, Section D, 700 Robbins Ave., Philadelphia, PA 19111-50941Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.fiber-
16、reinforced compositeany composite material consist-ing of a matrix reinforced by continuous or discontinuousfibers.filamentary compositea composite material reinforcedwith continuous fibers.unidirectional fiber-reinforced compositeany fiber-reinforced composite with all fibers aligned in a singledir
17、ection.continuous filament yarn, ntwo or more continuous fila-ments twisted into a single fiber bundle.crossply laminatea laminate composed of only 0 and 90plies. This is not necessarily symmetric.dam, na solid material (such as silicone rubber, steel, oraluminum), used in processing composites, to
18、contain thematrix material within defined boundaries or to preventcrowning of a processing bag.damage, nin structures and structural mechanics, a struc-tural anomaly in material or structure created by manufac-turing or service usage.damage resistance, nin structures and structural mechan-ics, a mea
19、sure of the relationship between the force, energy,or other parameter(s) associated with an event or sequence ofevents and the resulting damage size and type.DISCUSSIONDamage resistance increases as the force, energy, orother parameter increases for a given size or type of damage. Con-versely, damag
20、e resistance increases as damage decreases, for a givenapplied force, energy, or other parameter. Damage resistance anddamage tolerance are often confused. A material or structure with highdamage resistance will incur less physical damage from a given event.Materials or structures with high damage t
21、olerance may incur varyinglevels of physical damage but will have high amounts of remainingfunctionality.Adamage-resistant material or structure may, or may not,be considered damage tolerant.damage tolerance, n1) in structures and structure materi-als, a measure of the relationship between damage si
22、ze andtype and the level of a performance parameter, such asstiffness or strength, at which the structure or structuralmaterial can operate for a particular loading condition; 2) instructural systems, a measure of the ability of such systemsto function at designated performance parameters (for ex-am
23、ple, magnitude, length of time, and type of loading(s)without system failure in the presence of a particular orspecified level of damage.DISCUSSIONDamage tolerance involves, and can be provided by, anumber of factors operating at a number of levels: structural material,structural, and overall system
24、. These factors include 1) basic materialability to operate with damage present (often referred to as the residualstrength aspect), 2) damage growth resistance and containment pro-vided by material and structural considerations, and 3) system inspec-tion and maintenance plans which allow the damage
25、to be detected andcorrected and which depend upon material, structural, and operationalconsiderations.Damage tolerance increases as the damage size increases for a givenlevel of a performance parameter. Damage tolerance increases as thelevel of the performance parameter increases for a given damage
26、size.Damage tolerance depends upon the type of loading which is applied.For example, the damage tolerance for a compressive load can be, andgenerally is, different than for the same level of tensile load.Damage resistance is often confused with damage tolerance. Dam-age tolerance is directly related
27、 only to the size and type of damagewhile being only indirectly related to how the damage was created (seedamage resistance). Thus, damage tolerance is distinct from damageresistance.debonda deliberate separation of a bonded joint or interface,usually for repair or rework purposes.debulk, vto decrea
28、se voids between lamina before laminateconsolidation through use of vacuum or by mechanicalmeans.DISCUSSIONLaminae can be debulked at ambient or elevatedtemperatures.delaminationseparation of plies in a laminate. This may belocal or may cover a large area in the laminate.denier, na direct numbering
29、system for expressing lineardensity, equal to the mass in grams per 9000 metres of yarn,filament, fiber, or other textile strand.disbondan area within a bonded interface between twoadherents in which an adhesive or cohesive failure hasoccurred. It may occur at any time during the life of thestructur
30、e and may arise from a wide variety of causes. It issometimes used to describe an area of separation betweentwo laminae in the finished laminate (the term “delamina-tion” is preferred).discontinuous fibera polycrystalline or amorphous fiberthat is discontinuous within the sample or component or that
31、has one or both ends inside of the stress field underconsideration. The minimum diameter of a discontinuousfiber is not limited, but the maximum diameter may notexceed 0.25 mm (0.010 in.).end, nin fibrous composites, a general term for a continuous,ordered assembly of essentially parallel, collimate
32、d fila-ments, with or without twist.DISCUSSIONThis 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
33、by a knitting process.nonwoven fabric, na cloth constructed by bonding orinterlocking, or both (but not interlacing) fiber by anycombination of mechanical, chemical, thermal, or solventmeans.plied yarn, na yarn formed by twisting together two ormore single yarns in one operation.DISCUSSIONPlying, wh
34、ich is done in the opposite direction from thetwist of each of the simple yarns, serves to counter the tendency ofsimple yarns to untwist.woven fabric, na cloth constructed by a weaving process.fabrication, nthe process of manufacturing, forming, con-structing, or assembling a product or component.f
35、iber, none or more filaments in an ordered assemblage.D 3878 072DISCUSSIONThere are a number of general and specific terms thatdefine specific types of fiber forms. The relationship between fiber formterms is shown in Table 1.fiber contentthe amount of fiber present in a compositeexpressed either as
36、 percent by weight or percent by volume.This is sometimes stated as a fraction, that is, fiber volumefraction.fiber volume fractionsee fiber content.filament, na fibrous form of matter with an aspect ratio 10and an effective diameter =3.Other material properties mayfollow different rules. For exampl
37、e, thermal conductivity becomesquasi-isotropic for k=2,while strength properties generally are notcapable of true quasi-isotropy, only approximating this behavior.reinforcement, nin a composite material, the discrete con-stituent of a composite material, either fiber or particle,which is contained w
38、ithin the matrix, with a purpose ofincreasing the strength, or stiffness, or both.resina solid or pseudosolid organic material often of highmolecular weight, which exhibits a tendency to flow whensubjected to stress, usually has a softening or melting range,and usually fractures conchoidally.resin c
39、ontentsee matrix content.roving, nin fibrous composites, large filament count tow.(See also tow and filament count.)satin, adjdescription of a weave pattern in which warp yarnspass unbound (“float”) over several fill yarns before crossingunder a single fill yarn.DISCUSSIONA satin weave is characteri
40、zed by parallel fibers and nodiagonal pattern.selvage, nthe woven edge portion of a fabric parallel to thewarp.single yarnSee single yarn under yarn.stacking sequencethe arrangement of ply orientations andmaterial components in a laminate specified with respect tosome reference direction.staple, na
41、collection of discontinuous filaments of spinnablelength that are natural, manufactured directly in a shortlength, or cut from continuous filaments.strandin fibrous composites, Synonym for tow.symmetric laminatea laminate in which the stacking se-quence for the plies located on one side of the geome
42、tricmidplane are the mirror image of the stacking sequence onthe other side of the midplane.tab, na piece of material used to hold the laminate specimenin a grip or fixture for testing so that the laminate is notdamaged and is adequately supported.textile, na general term applied to fibers and organ
43、izedassemblies of fibers with sufficient integrity to retain theorganization.DISCUSSIONOriginally limited to woven fabrics, this term is nowalso applied to fibers, yarn intermediates, yarns, woven and nonwovenfabrics, braids, knits, and preforms, as illustrated in Fig. 1.thermoplastica plastic that
44、repeatedly can be softened byheating and hardened by cooling through a temperaturerange characteristic of the plastic, and that in the softenedstate can be shaped by flow into articles by molding orextrusion.thermoseta class of polymers that, when cured using heat,chemical, or other means, changes i
45、nto a substantiallyinfusible and insoluble material.towin fibrous composites, a continuous, ordered assembly ofessentially parallel, collimated filaments, normally withouttwist and of continuous filaments (Synonyms: strand andsilver).twist, nin fibrous composites, a measure of the number ofturns per
46、 unit length a fiber bundle makes around its axis.DISCUSSIONTwist is noted as being either S-twist or Z-twist,where the shape of the letters are used as a mnemonic to describe thedirection of the twist. Following the right-hand rule along the axis ofthe fiber bundle, Z-twist is a positive twist and
47、S-twist is a negativetwist. In addition, U is often used to represent no twist (untwisted) andN no twist (never twisted).voidany pocket of enclosed gas or air within a composite.void content, nthe volume percentage of voids in a com-posite.D 3878 074warp, n(1) the yarn running lengthwise in a woven
48、fabric;(2) a group of yarns in long lengths and approximatelyparallel, put on beams or warp reels for further textileprocessing including weaving, knitting, twisting, dyeing,and so forth. D 123warp nested, adjlaid up so that warp plies alternate in thepattern: warp surface up, warp surface down.warp
49、 surface, nthe ply surface that shows the larger area ofwarp tows with respect to fill tows.DISCUSSIONFabrics in which both surfaces show an equal area ofwarp tows with respect to fill tows do not have a warp surface.weave, vinterlaces, in a specific pattern, strands or yarnsoriented in two or more directions in a planar textile process.windinga process in which continuous material is appliedunder controlled tension to a form in a predeterminedgeometric relationship to make a str
