ASTM D6415/D6415M-06ae1

Standard Test Method for Measuring the Curved Beam Strength of a Fiber-Reinforced Polymer-Matrix Composite

SIGNIFICANCE AND USE
Out-of-plane stress analyses are not easily performed. Failure criteria are varied and poorly validated. Interlaminar allowables are not readily available. However, stress analysts routinely encounter structural details in which they cannot ignore the out-of-plane loads. This test method is designed to produce out-of-plane structural failure data for structural design and analysis, quality assurance, and research and development. For unidirectional specimens, this test method is designed to produce interlaminar tensile strength data. Factors that influence the curved beam strength and should therefore be reported include the following: material, methods of material preparation, methods of processing and specimen fabrication, specimen preparation, specimen conditioning, environment of testing, speed of testing, time at temperature, void content, and volume percent reinforcement.
SCOPE
1.1 This test method determines the curved beam strength of a continuous fiber-reinforced composite material using a 90 curved beam specimen (Fig. 1 and Fig. 2). The curved beam consists of two straight legs connected by a 90 bend with a 6.4-mm [0.25 in.] inner radius. An out-of-plane (through-the-thickness) tensile stress is produced in the curved region of the specimen when force is applied. This test method is limited to use with composites consisting of layers of fabric or layers of unidirectional fibers.
1.2 This test method may also be used to measure the interlaminar tensile strength if a unidirectional specimen is used where the fibers run continuously along the legs and around the bend.
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 and health practices and determine the applicability of regulatory limitations prior to use.
1.3 The values stated in either SI units or inch-pound units are to be regarded separately as standard. Within the text the inch-pound units are shown in brackets. The values stated in each system are not exact equivalents; therefore, each system must be used independently of the other. Combining values from the two systems may result in nonconformance with the standard.

General Information

• Status: Historical
• Publication Date: 28-Feb-2006
• ICS: 83.120 - Reinforced plastics
• Technical Committee: D30 - Composite Materials
• Drafting Committee: D30.06 - Interlaminar Properties

Relations

• Replaces: ASTM D6415/D6415M-06 - Standard Test Method for Measuring the Curved Beam Strength of a Fiber-Reinforced Polymer-Matrix Composite
• Effective Date: 01-Mar-2006
• Referred By: ASTM D4762-18 - Standard Guide for Testing Polymer Matrix Composite Materials
• Effective Date: 01-Mar-2006

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
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Designation: D6415/D6415M − 06a
StandardTest Method for
Measuring the Curved Beam Strength of a Fiber-Reinforced
1
Polymer-Matrix Composite
This standard is issued under the fixed designation D6415/D6415M; 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.
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ε NOTE—In Paragraph 1.1, 0.25 mm was corrected to 0.25 in. and at the end of Paragraph 7.1.2, reference to 11.3 was
added editorially in January 2007.
1. Scope D792Test Methods for Density and Specific Gravity (Rela-
tive Density) of Plastics by Displacement
1.1 Thistestmethoddeterminesthecurvedbeamstrengthof
D883Terminology Relating to Plastics
a continuous fiber-reinforced composite material using a 90°
D3171Test Methods for Constituent Content of Composite
curved beam specimen (Fig. 1 and Fig. 2). The curved beam
Materials
consists of two straight legs connected by a 90° bend with a
D3878Terminology for Composite Materials
6.4-mm [0.25 in.] inner radius. An out-of-plane (through-the-
D5229/D5229MTestMethodforMoistureAbsorptionProp-
thickness) tensile stress is produced in the curved region of the
erties and Equilibrium Conditioning of Polymer Matrix
specimen when force is applied. This test method is limited to
Composite Materials
use with composites consisting of layers of fabric or layers of
D5687/D5687MGuide for Preparation of Flat Composite
unidirectional fibers.
Panels with Processing Guidelines for Specimen Prepara-
1.2 This test method may also be used to measure the
tion
interlaminar tensile strength if a unidirectional specimen is
E4Practices for Force Verification of Testing Machines
used where the fibers run continuously along the legs and
E6Terminology Relating to Methods of Mechanical Testing
around the bend.
E122PracticeforCalculatingSampleSizetoEstimate,With
1.3 This standard does not purport to address all of the Specified Precision, the Average for a Characteristic of a
safety concerns, if any, associated with its use. It is the
Lot or Process
responsibility of the user of this standard to establish appro- E177Practice for Use of the Terms Precision and Bias in
priate safety and health practices and determine the applica- ASTM Test Methods
bility of regulatory limitations prior to use.
E456Terminology Relating to Quality and Statistics
1.4 The values stated in either SI units or inch-pound units E1309 Guide for Identification of Fiber-Reinforced
are to be regarded separately as standard. Within the text the
Polymer-Matrix Composite Materials in Databases
inch-pound units are shown in brackets. The values stated in E1434Guide for Recording Mechanical Test Data of Fiber-
each system are not exact equivalents; therefore, each system
Reinforced Composite Materials in Databases
must be used independently of the other. Combining values E1471Guide for Identification of Fibers, Fillers, and Core
from the two systems may result in nonconformance with the
Materials in Computerized Material Property Databases
standard.
3. Terminology
2. Referenced Documents
3.1 Definitions—Terminology D3878 defines terms relating
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to high-modulus fibers and their composites. Terminology
2.1 ASTM Standards:
D883definestermsrelatingtoplastics.TerminologyE6defines
terms relating to mechanical testing. Terminology E456 and
1 Practice E177 define terms relating to statistics. In the event of
This test method is under the jurisdiction of ASTM Committee D30 on
Composite Materials and is the direct responsibility of D30.06 on Interlaminar a conflict between terms, Terminology D3878 shall have
Properties.
precedence over the other terminologies.
Current edition approved March 1, 2006. Published March 2006. Originally
approved in 1999. Last previous edition approved in 2006 as D6415–06. DOI: 3.2 Definitions of Terms Specific to This Standard:
10.1520/D6415_D6415M-06AE01.
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NOTE 1—If the term represents a physical quantity, its analytical
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
dimensionsarestatedimmediatelyfollowingtheterm(orlettersymbol)in
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on fundamental dimension form, using the following ASTM standard sym-
the ASTM website. bology for fundamental dimensions, shown within square brackets: [M]
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D6415/D6415M − 06a
3.3.11 M = applied moment (see 3.2.1).
3.3.12 P = total force applied to the four-point-bending
fixture.
max
3.3
...