ASTM D2291/D2291M-22

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it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D2291/D2291M − 16 D2291/D2291M − 22
Standard Practice for
Fabrication of Ring Test Specimens for Glass-Resin
Composites
This standard is issued under the fixed designation D2291/D2291M; the number immediately following the designation indicates the
year of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last
reapproval. A superscript 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. Scope*
1.1 This practice is intended for use in the fabrication of ring-type test specimens to be used in the evaluation of the mechanical
properties of reinforcement and resins in a composite structure. The practice outlines the steps in the preparation of the test
specimens, including the final specimen machining where applicable. FourThree final ring configurations are included.
1.2 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each
system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the
two systems may result in nonconformance with the standard.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use.
NOTE 1—There is no known ISO equivalent to this practice.
1.4 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2.1 ASTM Standards:
D618 Practice for Conditioning Plastics for Testing
D883 Terminology Relating to Plastics
D2290 Test Method for Apparent Hoop Tensile Strength of Plastic or Reinforced Plastic Pipe
D2344/D2344M Test Method for Short-Beam Strength of Polymer Matrix Composite Materials and Their Laminates
3. Terminology
3.1 For definitions of terms which apply to this practice, see Terminology D883.
This practice is under the jurisdiction of ASTM Committee D20 on Plastics and is the direct responsibility of Subcommittee D20.18 on Reinforced Thermosetting Plastics.
Current edition approved Sept. 1, 2016Nov. 1, 2022. Published September 2016November 2022. Originally approved in 1964. Last previous edition approved in 20092016
as D2291 - 09.D2291 - 16. DOI: 10.1520/D2291_D2291M-16.10.1520/D2291_D2291M-22.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
*A Summary of Changes section appears at the end of this standard
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D2291/D2291M − 22
FIG. 1 Suggested Single-Ring Mold
4. Significance and Use
4.1 This practice provides a uniform procedure for fabricating glass fiber/thermoset resin ring samples for use as test specimens.
Specimens so prepared can be used in Test Methods D2290 and D2344/D2344M.
5. Apparatus
5.1 Winding Machine—The winding machine mayshall consist of any adequate superstructure for mounting impregnated
reinforcement or components for application of resin to the reinforcement, tensioning the reinforcement, and collecting the wetted,
tensioned material on a mold or mandrel of the desired size.
5.2 Tension Measuring System—Any device suitable for measurement of the tension applied to the wetted reinforcement. The
device shall be capable of measuring the tension accurately to within 65 %.use of a tension measuring system is optional for
measurement of the tension applied to the wetted reinforcement.
5.3 The single-ring fabrication mold on which the wetted reinforcement is collected shall be constructed as shown in Fig. 1. For
cylinder fabrication from which rings are to be cut, a mandrel with the proper diameter fitted to a suitable winding machine shall
be used to collect the wetted reinforcement. The surfaces of the mold or mandrel that contact the ring specimens shall be coated
or otherwise treated to prevent sticking of the ring or cylinder in the mold or on the mandrel.
5.4 Curing Ovens—Ovens having adequate range in temperature to produce a fully cured specimen shall be available for use.
Control of the curing-postcuring temperatures to within 69°F (65°C) is required.
6. Storage and Conditioning of Components
6.1 Glass rovings and yarns for use in fabrication of ring test specimens shall be stored in a dry place, not subject to temperature
extremes, or as specified by the glass producer. Prior to use, the rovings shall be conditioned in accordance with Procedure A of
Practice D618, which requires 40 hours at 23°C 6 2°C and a 50 % relative humidity 610 %.
6.2 Resins to be used in the fabrication of ring test specimens shall be stored in closed containers at a temperature specified by
the supplier. In addition, no resin shall be used that has been stored for a period in excess of the shelf life recommended by the
supplier. Prior to fabrication of the test specimen, the resin shall be heated as necessary to provide sufficient lowering of the
viscosity to produce good wetting of the reinforcement strand.
6.3 PreimpregnatedPre-impregnated materials received for the preparation of ring test specimens shall be stored in a closed
container at a temperature as recommended by the supplier. Before winding, they shall be removed from storage and conditioned
as recommended by the supplier or in accordance with Procedure A of Methods D618.
7. Procedure for Dry Reinforcement
7.1 Fig. 2 is a schematic diagram of thean example of a system for wetting, tensioning, and collecting the reinforcement.
D2291/D2291M − 22
FIG. 2 Schematic Diagram Example of Wet Roving Ring Winding Apparatus
7.1.1 Mounting Reinforcement Packages:
7.1.1.1 Outside Pull Packages—Mount the reinforcement package in a convenient location within the superstructure of the
winding machine. Provide sufficient braking of the axle of the package to prevent free-wheeling. This should be a minimum
tension.
7.1.1.2 Inside Pull Packages—Mount the reinforcement package so that the roving is pulled from the inside of the package and
passes through a guide eye such that the roving does not rub against the package edge or any sharp edges.
7.1.2 Application of Resin—The reinforcement leaving the package shall pass immediately into the resin bath. Heat the resin bath
sufficiently to lower the resin viscosity to a workable range. As the reinforcement is pulled from the resin bath, remove excess resin
by any convenient method that results in a minimum amount of fraying or breakage of the reinforcement.
7.1.3 Tensioning—After leaving the resin bath, pass the rein
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