ASTM F2921-2011 Standard Terminology for Additive ManufacturingCoordinate Systems and Test Methodologies《叠层制造中所用的坐标系统和测试方法的标准术语》.pdf

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1、Designation: F2921 11Standard Terminology forAdditive ManufacturingCoordinate Systems and TestMethodologies1This standard is issued under the fixed designation F2921; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last

2、 revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This terminology includes terms, definitions of terms,descriptions of terms, nomenclature, and acronyms associatedwith coo

3、rdinate systems and testing methodologies for additivemanufacturing (AM) technologies in an effort to standardizeterminology used by AM users, producers, researchers, educa-tors, press/media, and others, particularly when reportingresults from testing of parts made on AM systems. Termsincluded cover

4、 definitions for machines/systems and theircoordinate systems plus the location and orientation of parts. Itis intended, where possible, to be compliant with ISO 841 andto clarify the specific adaptation of those principles to additivemanufacturing.1.2 This standard does not purport to address all o

5、f thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D638 Test Method for Te

6、nsile Properties of PlasticsE8/E8M Test Methods for Tension Testing of MetallicMaterialsF2792 Terminology for Additive Manufacturing Technolo-gies2.2 ISO Standard:3ISO 841 Industrial Automation Systems and IntegrationNumerical Control of MachinesCoordinate System andMotion Nomenclature3. Significanc

7、e and Use3.1 Although many additive manufacturing systems arebased heavily upon the principles of Computer NumericalControl (CNC), the coordinate systems and nomenclaturespecific to CNC are not sufficient to be applicable across thefull spectrum of additive manufacturing equipment. This ter-minology

8、 expands upon the principles of ISO 841 and appliesthem specifically to additive manufacturing. Although thisterminology is intended to complement ISO 841, if thereshould arise any conflict, this terminology shall have priorityfor additive manufacturing applications. For any issues notcovered in thi

9、s terminology, the principles in ISO 841 may beapplied.3.2 Furthermore, this terminology does not prescribe the useof any specific existing testing methodologies or standards thatpractitioners of AM may wish to employ for testing purposes;however, it is expected that practitioners will employ appro-

10、priate existing methodologies and standards to test parts madeby AM.4. Terminology4.1 DefinitionsDefinitions shall be in accordance withTerminology F2792 and the following:1This terminology is under the jurisdiction of ASTM Committee F42 onAdditive Manufacturing Technologies and is the direct respon

11、sibility of Subcom-mittee F42.01 on Test Methods.Current edition approved July 15, 2011. Published September 2011. DOI:10.1520/F292111.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume inf

12、ormation, refer to the standards Document Summary page onthe ASTM website.3Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959

13、, United States.Terms and DefinitionsAM Machines and their Coordinate Systemsbuild platform, nof a machine, any base which provides asurface upon which the build is started and supportedthroughout the build process (see A1.1).DISCUSSIONThe machine build platform may be solid or perforatedand made fr

14、om a wide variety of materials and constructions.DISCUSSIONIn some systems the parts are built attached to the buildplatform, either directly or through a support structure. In othersystems, such as powder bed systems, no direct mechanical fixturebetween the build and the platform may be required.bu

15、ild surface, narea where material is added, normally onthe last deposited layer which becomes the foundation uponwhich the next layer is formed.DISCUSSIONFor the first layer the build surface is often the buildplatform.DISCUSSION If the orientation of the material deposition or consoli-dation means,

16、 or both, is variable, it may be defined relative to the buildsurface (for example, a blown powder head may be kept normal to it.See also Z axis discussion).front, nof a machine, shall be designated by the machinebuilder.DISCUSSIONGenerally, this is the side of the machine that theoperator faces to

17、access the user interface or primary viewing window,or both. (See A1.1).machine coordinate system, na three-dimensional Carte-sian coordinate system as defined by a fixed point on thebuild platform “with the three principal axes labeled X, Y,and Z, with rotary axes about each of theses axes labeled

18、A,B, and C, respectively” (see A1.1, A1.2, and A1.3) as statedin ISO 841.origin, na designated reference point at which the threeprimary axes in a Cartesian coordinate system intersect.Synonyms: zero point, or (0, 0, 0) when using X, Y, and Zcoordinates.build volume origin, nshall be located at the

19、center of thebuild platform fixed on the build facing surface.DISCUSSIONThis is a universal origin reserved for the purpose ofidentifying the location of parts within the build volume. (See A1.1 andA1.2).machine origin, norigin as defined by the original equip-ment manufacturer. Synonyms: machine ho

20、me, machinezero point.Z axis, nof a machine, for processes employing planarlayerwise addition of material, shall run normal to the layers.(See A1.1 and A1.2.)DISCUSSIONFor processes employing planar layerwise addition ofmaterial, the positive Z shall be the direction from the first layer to thesubse

21、quent layers (see A1.1 and A1.2).DISCUSSIONWhere addition of material is possible from multipledirections (such as with blown powder systems), the Z axis may beidentified according to the principles in ISO 841 (section 4.3.3) whichaddresses “swiveling or gimballing.”X axis, nof a machine, shall run

22、perpendicular to the Z axisand parallel to the front of the machine. (SeeA1.1 andA1.2.)DISCUSSIONWhere possible, the X axis shall be horizontal andparallel with one of the edges of the build platform.DISCUSSIONThe positive X direction shall be from left to right asviewed from the front of the machin

23、e while facing toward the buildvolume origin.Y axis, nof a machine, shall run perpendicular to the Z andX axes with positive direction defined to make a right handset of coordinates as specified in ISO 841.DISCUSSIONWhere possible, the Y axis shall be horizontal andparallel with one of the edges of

24、the build platform.DISCUSSIONIn the most common case of an upwards Z positivedirection, the positive Y direction shall be from the front to the back ofthe machine as viewed from the front of the machine (see A1.1).DISCUSSIONIn the case of building in the downwards Z positivedirection the positive Y

25、direction shall be from the back of the machineto the front as viewed from the front of the machine (see A1.2).Terms and DefinitionsLocation and Orientation of Parts Within the Build Volumearbitrarily oriented minimum bounding box, nof a part,the minimum perimeter cuboid that can span the maximumext

26、ents of the points on the surface of a 3D part calculatedwithout any constraints on the resulting orientation of thebox (see A1.4 and A1.5).DISCUSSIONWhere the manufactured part includes the test geometryplus additional external features (for example, labels, tabs or raisedlettering), the bounding b

27、ox may be specified according to the test partgeometry excluding the additional external features if noted.geometric center, nof a bounding box, location at thearithmetic middle of the bounding box of the part. Synonym:centroid.DISCUSSIONThe center of the bounding box may lie outside the part.initia

28、l build orientation, nof a part, is the orientation of thepart as first placed in the build volume and becomes thereference for any further part reorientation (see A1.6).DISCUSSIONThe initial build orientation is most easily communi-cated via 3D computer models (which can be interrogated for partpos

29、ition and orientation relative to the build volume origin). Wherepractical, the initial build orientation may be designated as the partorientation in the 3D computer model. Without electronic transfer ofcomputer models, it should be documented with image(s) of the part(s)within the build volume and

30、their orientation relative to the buildvolume origin (see A1.6 and A1.7).F2921 112orthogonal orientation notation, n of a parts initial buildorientation, may be used when the intended build orientationfor a part is such that its arbitrarily oriented minimumbounding box is aligned parallel to the X,

31、Y, and Z axes of thebuild volume origin (as shown in A1.5(c), its orientationmay be described by listing which axis is parallel to thelongest overall dimension of the bounding box first, fol-lowed by the axis which is parallel to the second longestoverall dimension of the bounding box second, follow

32、ed bythe axis which is parallel to the third longest overalldimension of the bounding box.DISCUSSION For example, a specimen which is placed so that itslongest dimension is parallel to the Z axis, the second longestdimension is parallel to the X axis, and its shortest overall dimension isparallel to

33、 the Y axis shall be defined as having a ZXY orientation (seeA1.8 and A1.10 for examples).DISCUSSIONWhere symmetry allows unambiguous designation oforientation by listing fewer than three axes (in descending order oflength), orthogonal orientation notation can be further abbreviated (seeA1.9 and A1.

34、10).DISCUSSIONSome combinations of part symmetry in an orthogonalinitial build orientation fully define only one possible orientation andtherefore no image is required to communicate the initial buildorientation. This is the case for parts like the D638 dog bone specimenin A1.10, which are bilateral

35、ly symmetrical (see A1.9) through itsgeometric center in the XY, XZ, YZ planes and have no rotationalsymmetry. This is also the case for parts like the round tension bar (seeA1.10) which have 360 rotational symmetry through a center axis andare also bilaterally symmetrical across the plane bisecting

36、 the partperpendicular to the axis of rotational symmetry. Normally, an image isrequired to identify initial build orientation when parts have featureswith less than 360 rotational symmetry (see A1.7).part location, nwithin the build volume should be specifiedby the X, Y, and Z coordinates for the p

37、osition of thegeometric center of each parts arbitrarily oriented minimumbounding box with respect to the build volume origin (seeA1.11 and A1.12).DISCUSSIONWhere finding the arbitrarily oriented minimum bound-ing box is not possible or practical, the coordinates of the center of theparts bounding b

38、ox (aligned orthogonally to the build volume origin)when the part is in its initial build orientation may be used for definingpart location.part reorientation, nthe reorientation of parts within thebuild volume shall be specified by rotation around thegeometric center of the parts arbitrarily orient

39、ed minimumbounding box in the sequence of A, B, and C (see A1.3 andA1.12) from a specified initial build orientation of that part.DISCUSSIONOnly non-zero angles need to be listed. For example,see A1.12 where the front row of parts are reoriented to A=0,B= +45,C= 0 from an initial build orientation Z

40、 and are identified as B+45 fromZ.5. Keywords5.1 additive manufacturing; test methods; machine coordi-nate system; part location; part orientationF2921 113ANNEX(Mandatory Information)A1. IMAGES REFERRED TO IN THE DEFINITIONSA1.1 See Fig. A1.1.A1.2 See Fig. A1.2.FIG. A1.1 Generic (Upward Building) Ad

41、ditive Manufacturing Machine/SystemFIG. A1.2 Generic (Downward Building) Additive Manufacturing Machine/SystemF2921 114A1.3 See Fig. A1.3.A1.3.1 As per ISO 841 when the thumb of the right handpoints in the positive X, Y,orZ directions, then positiverotation will be the direction from the hand to the

42、 finger tips.A1.4 See Fig. A1.4.FIG. A1.3 Right Hand Rule for Positive Rotations with Referenceto the Build Volume OriginFIG. A1.4 Example of an Arbitrarily Oriented Minimum Bounding BoxF2921 115A1.5 See Fig. A1.5.A1.5.1 Fig. A1.5 shows (a) a pressure plate in an arbitraryorientation and its boundin

43、g box aligned to the build volumeorigin, (b) the same geometry in the same orientation with itsarbitrarily oriented minimum bounding box, and (c) the samepart now re-oriented so that its minimum bounding box isparallel to the build volume origin.FIG. A1.5 Examples of Different Types of Bounding Boxe

44、sF2921 116A1.6 See Fig. A1.6.A1.6.1 The pressure plate is shown in its intended buildorientation relative to the build volume origin (for a perspec-tive view of this part in the same orientation see Fig. A1.5(c).The overall dimensions of its bounding box are provided sothat the geometric center can

45、be calculated. Also the alignmentof the major features (the bolt circle) is shown with the centerlines.A1.6.2 DiscussionIn this example the initial build orien-tation is such that the arbitrarily oriented minimum boundingbox has been aligned to the build volume origin in one of thesix orthogonal ali

46、gnments, which is convenient (especiallywhen specifying multiple occurrences of the part geometrywith reorientation) but it is not a requirement for the initialbuild orientation. For example, if thoroughly dimensioned, theorientation of this part as shown in Fig. A1.5(a) may be usedas an initial bui

47、ld orientation as well. In practice, the morecomplicated the part geometry and increased number oforientations the more likely this will be communicated usingthree-dimensional computer models, rather than methods for2D reporting.FIG. A1.6 Initial Build OrientationF2921 117A1.7 See Fig. A1.7.A1.7.1 B

48、ecause a fi b fi c (even though they share the sameorthogonal orientation notation for their initial build orienta-tions).A1.7.2 Even when the arbitrarily oriented minimum bound-ing box is aligned to the build volume origin, there are stillmultiple orientations possible for many part geometries (esp

49、e-cially when there is less than 360 rotated symmetry, such asthe 60 rotated bolt circle in the pressure plate shown). In orderto clarify which orientation is intended, a visual depiction isneeded.FIG. A1.7 Why is a Picture Normally Required to Communicate the Initial Build Orientation?F2921 118A1.8 See Fig. A1.8.A1.8.1 Fig. A1.8 shows the possible alignments for anarbitrarily oriented minimum bounding box with reference tothe build volume origin and their notations as described inSection 4 (orthogonal orientation not