1、Designation: D 2291 09Standard Practice forFabrication of Ring Test Specimens for Glass-ResinComposites1This standard is issued under the fixed designation D 2291; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last re
2、vision. A number 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 Department of Defense.1. Scope*1.1 This practice is intended for use in the fa
3、brication ofring-type test specimens to be used in the evaluation of themechanical properties of reinforcement and resins in a com-posite structure. The practice outlines the steps in the prepara-tion of the test specimens, including the final specimenmachining where applicable. Four final ring conf
4、igurations areincluded.1.2 The values stated in either SI units of inch-pound unitsare to be regarded separately as standard. The values stated ineach system may not be exact equivalents; therefore, eachsystem shall be used independently of the other. Combiningvalues from the two systems may result
5、in nonconformancewith the standard.1.3 This standard does not purport to address all of 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 limit
6、ations prior to use.NOTE 1There is no known ISO equivalent to this practice.2. Referenced Documents2.1 ASTM Standards:2D 618 Practice for Conditioning Plastics for TestingD 883 Terminology Relating to PlasticsD 2290 Test Method for Apparent Hoop Tensile Strength ofPlastic or Reinforced Plastic Pipe
7、by Split Disk MethodD 2344/D 2344M Test Method for Short-Beam Strength ofPolymer Matrix Composite Materials and Their Laminates3. Terminology3.1 For definitions of terms which apply to this practice, seeTerminology D 883.4. Significance and Use4.1 This practice provides a uniform procedure for fabri
8、cat-ing glass fiber/thermoset resin ring samples for use as testspecimens. Specimens so prepared can be used in Test MethodsD 2290 and D 2344/D 2344M.5. Apparatus5.1 Winding MachineThe winding machine may consistof any adequate superstructure for mounting impregnatedreinforcement or components for a
9、pplication of resin to thereinforcement, tensioning the reinforcement, and collecting thewetted, tensioned material on a mold or mandrel of the desiredsize.5.2 Tension Measuring SystemAny device suitable formeasurement of the tension applied to the wetted reinforce-ment. The device shall be capable
10、of measuring the tensionaccurately to within 65%.5.3 The single-ring fabrication mold on which the wettedreinforcement is collected shall be constructed as shown in Fig.1. For cylinder fabrication from which rings are to be cut, amandrel with the proper diameter fitted to a suitable windingmachine s
11、hall be used to collect the wetted reinforcement. Thesurfaces of the mold or mandrel that contact the ring specimensshall be coated or otherwise treated to prevent sticking of thering or cylinder in the mold or on the mandrel.5.4 Curing OvensOvens having adequate range in tem-perature to produce a f
12、ully cured specimen shall be availablefor use. Control of the curing-postcuring temperatures towithin 69F (65C) is required.6. Storage and Conditioning of Components6.1 Glass rovings and yarns for use in fabrication of ring testspecimens shall be stored in a dry place, not subject totemperature extr
13、emes, or as specified by the glass producer.Prior to use, the rovings shall be conditioned in accordancewith ProcedureAof Practice D 618, which requires 40 hours at23C 6 2C and a 50 % relative humidity 610 %.6.2 Resins to be used in the fabrication of ring test speci-mens shall be stored in closed c
14、ontainers at a temperaturespecified by the supplier. In addition, no resin shall be used thathas been stored for a period in excess of the shelf liferecommended by the supplier. Prior to fabrication of the test1This practice is under the jurisdiction ofASTM Committee D20 on Plastics andis the direct
15、 responsibility of Subcommittee D20.18 on Reinforced ThermosettingPlastics.Current edition approved Sept. 1, 2009. Published September 2009. Originallyapproved in 1964. Last previous edition approved in 2003 as D 2291 - 03.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orconta
16、ct ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1*A Summary of Changes section appears at the end of this standard.Copyright (C) ASTM International, 100 Barr Harbour Dr. P.O. box C-700 W
17、est Conshohocken, Pennsylvania 19428-2959, United StatesCopyright by ASTM Intl (all rights reserved); Mon Oct 12 22:39:46 EDT 2009Downloaded/printed byGuo Dehua (CNIS) pursuant to License Agreement. No further reproductions authorized.specimen, the resin shall be heated as necessary to providesuffic
18、ient lowering of the viscosity to produce good wetting ofthe reinforcement strand.6.3 Preimpregnated materials received for the preparation ofring test specimens shall be stored in a closed container at atemperature as recommended by the supplier. Before winding,they shall be removed from storage an
19、d conditioned asrecommended by the supplier or in accordance with ProcedureA of Methods D 618.7. Procedure for Dry Reinforcement7.1 Fig. 2 is a schematic diagram of the system for wetting,tensioning, and collecting the reinforcement.7.1.1 Mounting Reinforcement PackagesMount the rein-forcement packa
20、ge in a convenient location within the super-structure of the winding machine. Provide sufficient braking ofthe axle of the package to prevent free-wheeling. This shouldbe a minimum tension.7.1.2 Application of ResinThe reinforcement leaving thepackage shall pass immediately into the resin bath. Hea
21、t theresin bath sufficiently to lower the resin viscosity to a workablerange. As the reinforcement is pulled from the resin bath,remove excess resin by any convenient method that results ina minimum amount of fraying or breakage of the reinforce-ment.7.1.3 TensioningAfter leaving the resin bath, pas
22、s thereinforcement over a pulley or a series of pulleys, adequatelybraked to impart the desired tension to the fibers. The tensionmay be monitored, by any convenient method, either periodi-cally or continuously during the winding operation. Limit thedeviation from the mean tension to 65 % from start
23、 to finish ofthe winding of a test specimen. The diameter of the tensionpulley(s) shall be a minimum of 3.0 in. (76.2 mm). Larger sizesshould be used when available. Take care that no slippage ofthe strand occurs over the pulley(s).7.1.4 Level-WindingPass the wetted reinforcementthrough a level-wind
24、ing guide and onto the mold. The guideshall be geared to the mold or mandrel or shall follow a cam insuch a manner that each revolution of the mold or mandrel willbe accompanied by a precision of the guide by an amountequivalent to one strand width.7.1.5 Collecting ReinforcementCollect the wetted re
25、in-forcement strand on a mold or mandrel that is mounted on theaxle of a variable-speed drive. The strand velocity through theresin bath shall be constant and shall be slow enough to givegood wetting of the reinforcement with the resin. Apply anadequate mold release agent to the mold or mandrel befo
26、rewinding is begun to assure easy removal of the specimen afterfabrication. Wind specimens to be tested without machiningthe surface to a thickness as indicated for the Type B specimen,Fig. 3. Build up Types A, B, and C specimens in Fig. 3 to athickness beyond that required for finished thickness. U
27、poncompletion of the winding process, secure the strand in such amanner as to retain the tension before cutting the strand andremoving the mold or mandrel from the winding machine.7.1.6 CuringTransfer the molds or mandrel to an ovenand polymerize the resin in the manner prescribed by themanufacturer
28、.NOTE 2Excess resin on the surface of the Type B specimen should beremoved if possible during cure.NOTE 3Many fabricating factors influence the mechanical propertiesof the rings such as the equipment system, resin system and age, operatortechniques, ambient conditions and conditioning, etc. For this
29、 reason it isbest to run a control material with each set of samples and to randomizethe fabrication order of the rings.7.1.7 Removing Rings from Mold or MandrelRemove thering specimens from the molds or mandrel in such a mannerthat delamination or other damage to the surfaces does notoccur. An arbo
30、r press may be used to apply force to separatethe mold parts in the single-ring process if required.7.1.8 Preparation of Specimens for Testing:7.1.8.1 WidthMold or machine the width of the Type A,B, C, and D specimens to the correct width.7.1.8.2 ThicknessDo not machine the thickness of theType B sp
31、ecimens. Machine the thickness of the Types A, C,and D specimens to the correct wall thickness.7.1.8.3 The dimensions of the finished test specimen aregiven in Fig. 3. Following the machining operation, thespecimen may be submitted to test or may be cut into flexuralor horizontal shear specimens as
32、desired. When cutting thesespecimens from the ring, take care that all cut surfaces areparallel to the radius of the ring.7.1.8.4 When fabricating composite specimens by machin-ing operations, a fine dust consisting of particles of fibers or thematrix material, or both, may be formed. These fine dus
33、ts canbe a serious health or safety hazard, or both. Adequateprotection should be afforded operating personnel and equip-ment. This may require adequate ventilation or dust collectingfacilities, or both, at a minimum.FIG. 1 Suggested Single-Ring MoldD 2291 092Copyright by ASTM Intl (all rights reser
34、ved); Mon Oct 12 22:39:46 EDT 2009Downloaded/printed byGuo Dehua (CNIS) pursuant to License Agreement. No further reproductions authorized.8. Procedure for Prepregs8.1 The procedure for the preparation of ring test specimensfrom preimpregnated material shall be identical to that de-scribed for dry r
35、oving, except omit 7.1.2 (see Fig. 4).9. Report9.1 The report shall include the following:9.1.1 Complete identification of all components in the ringsfabricated; including type, source, form of the resin system,reinforcement, or preimpregnated material. It shall also includethe history of the materi
36、al including, but not limited to, age andstorage conditions,9.1.2 Complete description of conditions under which therings were fabricated, including temperature and relative hu-midity,9.1.3 Complete description of the impregnation method,9.1.4 Resin wiping technique,9.1.5 Tension,9.1.6 Rate of windi
37、ng,9.1.7 Any special equipment or methods utilized,9.1.8 Type of specimen fabricated, single or cylinder,9.1.9 Mold materials used,9.1.10 Complete cure procedure, and9.1.11 Date of fabrication.10. Keywords10.1 composite; glass fiber; prepreg; ring samples; ringtensile testing; shear testing; specime
38、n preparation; thermosetresinFIG. 2 Schematic Diagram of Wet Roving Ring Winding ApparatusType of SpecimenInside Diameter, DIWidth, b Wall Thickness, din. mm in. mm in. mmA 5.750 6 0.002 146.05 6 0.05 0.250 6 0.005 6.35 6 0.127 0.060 6 0.002 1.52 6 0.05B 5.750 6 0.002 146.05 6 0.05 0.250 6 0.005 6.3
39、5 6 0.127 0.060 6 0.010 1.52 6 0.25C 5.750 6 0.002 146.05 6 0.05 0.250 6 0.005 6.35 6 0.127 0.125 6 0.002 3.18 6 0.05FIG. 3 Ring Test SpecimenD 2291 093Copyright by ASTM Intl (all rights reserved); Mon Oct 12 22:39:46 EDT 2009Downloaded/printed byGuo Dehua (CNIS) pursuant to License Agreement. No fu
40、rther reproductions authorized.SUMMARY OF CHANGESCommittee D20 has identified the location of selected changes to this standard since the last issue(D 2991 - 03) that may impact the use of this standard. (September 1, 2009)(1) Revised 6.1.ASTM International takes no position respecting the validity
41、of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject t
42、o revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters.
43、 Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is
44、copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceast
45、m.org (e-mail); or through the ASTM website(www.astm.org).FIG. 4 Schematic Diagram of Preimpregnated Roving Winding SystemD 2291 094Copyright by ASTM Intl (all rights reserved); Mon Oct 12 22:39:46 EDT 2009Downloaded/printed byGuo Dehua (CNIS) pursuant to License Agreement. No further reproductions authorized.
