ASTM B987/B987M-20

Standard Specification for Carbon Fiber Thermoset Polymer Matrix Composite Core (CFC) for use in Overhead Electrical Conductors

ABSTRACT
This specification covers carbon fiber composite core/thermoset (CFCC/TS) matrix for use in reinforcing or supporting overhead electrical conductors. It provides requirements for CFCC/TS materials and manufacture, including tensile strength, glass transition temperature, and minimum bending diameter. This specification also applies to classes of CFCC/TS, test classifications and number of tests and retests, actual density of the CFCC/TS, minimum thickness of the galvanic protection barrier layer, joints, workmanship, finish and appearance, inspection, certification, and packaging and package material. The tests covered by this specification are: tensile test and glass transition temperature test, bending test, dye penetrant testing after bending test, tensile test after bending test, heat exposure test, and heat/stress test.
SCOPE
1.1 This specification covers carbon fiber reinforced thermoset matrix composite core strength members for use in reinforcing or supporting overhead electrical conductors.  
1.2 This specification covers carbon fiber core diameters from 0.180 to 0.500 in. [4.57 to 12.7 mm], inclusive.  
1.3 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 non-conformance with the standard.  
1.4 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.5 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.

General Information

• Status: Published
• Publication Date: 31-Jul-2020
• ICS: 29.240.20 - Power transmission and distribution lines
• Technical Committee: B01 - Electrical Conductors
• Drafting Committee: B01.07 - Conductors of Light Metals

Relations

• Replaces: ASTM B987/B987M-17e1 - Standard Specification for Carbon Fiber Thermoset Polymer Matrix Composite Core (CFC) for use in Overhead Electrical Conductors
• Effective Date: 01-Aug-2020
• Refers: ASTM D7028-07(2024) - Standard Test Method for Glass Transition Temperature (DMA Tg) of Polymer Matrix Composites by Dynamic Mechanical Analysis (DMA)
• Effective Date: 01-Jan-2024
• Refers: ASTM D5117-17 - Standard Test Method for Dye Penetration of Solid Fiberglass Reinforced Pultruded Stock
• Effective Date: 15-Dec-2017
• Refers: ASTM D7028-07(2015) - Standard Test Method for Glass Transition Temperature (DMA Tg) of Polymer Matrix Composites by Dynamic Mechanical Analysis (DMA)
• Effective Date: 01-Aug-2015
• Refers: ASTM D5117-09 - Standard Test Method for Dye Penetration of Solid Fiberglass Reinforced Pultruded Stock
• Effective Date: 01-Sep-2009
• Refers: ASTM E29-08 - Standard Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications
• Effective Date: 01-Oct-2008
• Refers: ASTM D792-08 - Standard Test Methods for Density and Specific Gravity (Relative Density) of Plastics by Displacement
• Effective Date: 15-Jun-2008
• Refers: ASTM D3916-08 - Standard Test Method for Tensile Properties of Pultruded Glass-Fiber-Reinforced Plastic Rod
• Effective Date: 01-Mar-2008
• Refers: ASTM D7028-07 - Standard Test Method for Glass Transition Temperature (DMA Tg) of Polymer Matrix Composites by Dynamic Mechanical Analysis (DMA)
• Effective Date: 15-Dec-2007
• Refers: ASTM D7028-07e1 - Standard Test Method for Glass Transition Temperature (DMA Tg) of Polymer Matrix Composites by Dynamic Mechanical Analysis (DMA)
• Effective Date: 15-Dec-2007
• Refers: ASTM E29-06b - Standard Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications
• Effective Date: 15-Nov-2006
• Refers: ASTM E29-06a - Standard Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications
• Effective Date: 15-Sep-2006
• Refers: ASTM E29-06 - Standard Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications
• Effective Date: 01-May-2006
• Refers: ASTM D5423-93(2005) - Standard Specification for Forced-Convection Laboratory Ovens for Evaluation of Electrical Insulation (Withdrawn 2014)
• Effective Date: 01-Sep-2005
• Refers: ASTM E29-04 - Standard Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications
• Effective Date: 01-Dec-2004

Overview

ASTM B987/B987M-20, published by ASTM International, is the standard specification for Carbon Fiber Thermoset Polymer Matrix Composite Core (CFC) used in overhead electrical conductors. This specification outlines the essential criteria for materials, testing, manufacture, and performance of carbon fiber composite cores (CFCC/TS), integral for the reliability and longevity of overhead power transmission lines. The standard addresses all significant product attributes, including tensile strength, glass transition temperature, bending flexibility, density, and galvanic protection, helping ensure quality and uniformity in the production and application of carbon fiber composite cores in power infrastructure.

Key Topics

• Material Requirements

  • Carbon fiber reinforced thermoset polymer matrix as the core material
  • Galvanic protection barrier layer to prevent interaction between carbon fibers and aluminum conductor strands
  • Defined core diameters ranging from 0.180 to 0.500 inches (4.57 to 12.7 mm)

• Performance Properties

  • Minimum ultimate tensile strengths specified for standard, high, and extra high strength grades
  • Required glass transition temperature (Tg) of thermoset matrix for thermal stability
  • Specified minimum bending diameters to ensure flexibility during installation
  • Density and minimum layer thickness for galvanic protection included

• Testing and Validation

  • Mandatory routine and design validation tests:
    • Tensile strength testing
    • Glass transition temperature measurement
    • Density evaluation
    • Bending tests (including post-bending tensile and dye penetrant tests)
    • Heat exposure and heat/stress endurance tests
  • Requirements for the number of tests, retesting procedures, and criteria for conformance or rejection

• Manufacturing and Quality

  • Requirements for continuous carbon fiber tow with no internal joints
  • Permitted splicing of the galvanic protection barrier under controlled conditions
  • Specifications for workmanship, finish, and visual quality
  • Guidelines for inspection, certification, and package marking

Applications

ASTM B987/B987M-20 is critical in the electrical power transmission industry, specifically for:

• Overhead Electrical Conductors
  Carbon fiber composite core (CFC) is used as a strength member to reinforce or support overhead conductors, enabling increased capacity and reducing line sag compared to traditional steel cores.

• High-Temperature, Low-Sag (HTLS) Conductors
  CFCs offer superior mechanical and thermal properties, allowing conductors to operate at elevated temperatures with minimal elongation, making them suitable for grid modernization and infrastructure upgrades.

• Long-Span Transmission Lines
  The advanced strength-to-weight ratio and durability of CFCs are advantageous for crossing rivers, valleys, or other challenging terrains where long spans are necessary.

• Resilience & Reliability Upgrades
  Utilities seeking enhanced conductor performance against thermal cycling, environmental exposure, and mechanical stress can specify CFCs compliant with ASTM B987/B987M.

Related Standards

• ASTM D792 - Test Methods for Density and Specific Gravity (Relative Density) of Plastics by Displacement
• ASTM D3916 - Test Method for Tensile Properties of Pultruded Glass-Fiber-Reinforced Plastic Rod
• ASTM D5117 - Test Method for Dye Penetration of Solid Fiberglass Reinforced Pultruded Stock
• ASTM D5423 - Specification for Forced-Convection Laboratory Ovens for Evaluation of Electrical Insulation
• ASTM D7028 - Test Method for Glass Transition Temperature (DMA Tg) of Polymer Matrix Composites by Dynamic Mechanical Analysis (DMA)
• ASTM E29 - Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications

Keywords: carbon fiber composite core, ASTM B987/B987M, overhead electrical conductor, thermoset polymer matrix, galvanic protection, tensile strength, glass transition temperature, high-strength transmission lines, electrical standards, power infrastructure reliability.

Standards Content (Sample)

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.
Designation:B987/B987M −20
Standard Specification for
Carbon Fiber Thermoset Polymer Matrix Composite Core
(CFC) for use in Overhead Electrical Conductors
This standard is issued under the fixed designation B987/B987M; 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.
1. Scope D3916 Test Method for Tensile Properties of Pultruded
Glass-Fiber-Reinforced Plastic Rod
1.1 This specification covers carbon fiber reinforced ther-
D5117 Test Method for Dye Penetration of Solid Fiberglass
moset matrix composite core strength members for use in
Reinforced Pultruded Stock
reinforcing or supporting overhead electrical conductors.
D5423 Specification for Forced-Convection Laboratory Ov-
1.2 This specification covers carbon fiber core diameters
ens for Evaluation of Electrical Insulation
from 0.180 to 0.500 in. [4.57 to 12.7 mm], inclusive.
D7028 TestMethodforGlassTransitionTemperature(DMA
Tg) of Polymer Matrix Composites by Dynamic Mechani-
1.3 The values stated in either SI units or inch-pound units
are to be regarded separately as standard. The values stated in cal Analysis (DMA)
E29 Practice for Using Significant Digits in Test Data to
each system may not be exact equivalents; therefore, each
system shall be used independently of the other. Combining Determine Conformance with Specifications
values from the two systems may result in non-conformance
3. Terminology
with the standard.
3.1 Definitions of Terms Specific to This Standard:
1.4 This standard does not purport to address all of the
3.1.1 CFC (carbon fiber composite core/thermoset matrix),
safety concerns, if any, associated with its use. It is the
n—consisting of continuous carbon fiber tows held together by
responsibility of the user of this standard to establish appro-
a polymer matrix where the polymer is specifically a thermo-
priate safety, health, and environmental practices and deter-
setting polymer. The carbon fiber composite core is protected
mine the applicability of regulatory limitations prior to use.
with a galvanic protection barrier layer.
1.5 This international standard was developed in accor-
3.1.2 core, n—see CFC.
dance with internationally recognized principles on standard-
ization established in the Decision on Principles for the 3.1.3 design validation tests, n—the purpose of these tests is
Development of International Standards, Guides and Recom- to verify the suitability of the CFC design, materials, and
mendations issued by the World Trade Organization Technical method of manufacturing to meet the requirements in this
Barriers to Trade (TBT) Committee. specification. To ensure compliance with this specification,
these tests shall be performed on composite core samples at the
2. Referenced Documents
time of manufacture and be repeated whenever the design,
manufacturing method or the materials have changed. The
2.1 The following documents of the issue in effect on date
results of design validation tests are to be recorded and are
of material purchase form a part of this specification to the
considered valid for the whole class of CFC.
extent referenced herein.
2 3.1.4 DMA (dynamic mechanical analyzer), n—a device
2.2 ASTM Standards:
that measures the T of a polymer matrix or composite by
g
D792 Test Methods for Density and Specific Gravity (Rela-
subjecting the sample to an oscillating stress while heating the
tive Density) of Plastics by Displacement
specimen at a given heating rate.
3.1.5 galvanic protection barrier layer, n—anon-conductive
layer that prevents the carbon fiber of the composite core from
This specification is under the jurisdiction of ASTM Committee B01 on
Electrical Conductors and is the direct responsibility of Subcommittee B01.07 on
making contact with the aluminum strands used in the conduc-
Conductors of Light Metals.
tor.
Current edition approved Aug. 1, 2020. Published August 2020. Originally
ɛ1
3.1.6 glass transition temperature (T ), n—a temperature
approved in 2014. Last previous edition approved in 2017 as B987/B987M – 17 .
g
DOI: 10.1520/B0987_B0987M-20.
where the polymer matrix properties transition from a hard,
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
glassystatetoarubberystate.Thistemperatureisdefinedtobe
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
the temperature at which a curve defined by plotting loss
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. modulus versus temperature reaches its peak value.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
B987/B987M−20
3.1.7 loss modulus, n—represents the viscous portion of the 5.1.7 Order example: Five (5) lengths of 24 000 ft [7300 m]
polymer matrix response to the simultaneous application of each, 0.375 in. [9.53 mm] CFC, high strength grade, packaged
heat and stress; is proportional to the energy dissipated as heat onto wood nonreturnable reels, with certified test report.
by the composite sample in the DMAand reaches a maximum
6. Materials and Manufacture
value when the polymer matrix in the composite transitions
from the glassy to the rubbery state (T ).
g 6.1 The CFC shall consist of carbon fibers of suitable type
that are combined with a suitable heat resistant thermoset
3.1.8 lot, n—unless otherwise specified in the contract or
polymer matrix, and encased in a galvanic protection barrier
order, a lot shall consist of all coils of CFC of the same
layer.
diameter, produced from one continuous run of a fiber setup,
6.1.1 The galvanic protection barrier shall meet the require-
submitted for inspection at the same time.
ments set forth in this specification including thickness, mini-
3.1.9 matrix volume fraction, n—the amount of matrix resin
mum bending diameter, and dye penetrant after bending.
relative to fiber in a composite core. The matrix volume
6.2 The CFC shall meet the requirements set forth in this
fraction is calculated by subtracting the area of the glass and
specification, including tensile strength, glass transition tem-
carbon fibers from the total area of the part and then dividing
perature (T ) and minimum bending diameter.
by the total area of the part.
g
3.1.10 polymer matrix, n—a high molecular weight organic
7. Classes of CFC
material consisting of repeating chemical structures.
7.1 The classes of CFC products shall be designated by the
3.1.11 production unit, n—a reel, spool, or other package of
individual manufacturer and are designs that meet the specified
CFC that represents a single usable length.
strength grade, and are further defined as having cores with the
3.1.12 routine tests, n—tests that are performed by the
following properties:
manufacturer, and are intended to prove conformance to the
7.1.1 Meet the specified grade of strength.
specific requirements.
7.1.2 The area ratio of carbon fiber plus matrix resin to
galvanic protection layer is held within 610 %.
3.1.13 sample, n—a length of composite core removed from
7.1.3 The nominal matrix volume fraction is held within
the start or end of a CFC lot, and considered to have properties
63 % in a given strength grade of CFC.
representative of the lot.
7.1.4 Use the same thermoset polymer matrix resin (includ-
3.1.14 specimen, n—a length of composite core taken from
ing any fillers that are added to the polymer matrix) and same
a lot of CFC for testing purposes.
galvanic protection system (including any fillers).
3.1.15 tow, n—a bundle, containing multiple fibers. Tow
7.1.5 Have a core diameter within 615 % of the baseline
sizes range from 1 K (1000 fibers per bundle) to 50 K (50 000
diameterusedfordesignvalidationtests(seeExplanatoryNote
fibers per bundle).
2).
3.1.16 rated T —the minimum T value guaranteed by the
g g
8. Test Classifications and Number of Tests and Retests
supplier of the CFC.
8.1 Test requirements are classified as either design valida-
3.2 Product Code—Defines the strength grade for product
tion tests or routine tests as indicated in Table 1.
producedtothisspecification:StandardStrength(CodeCFC1);
High Strength (Code CFC2); and Extra High Strength (Code
CFC3).
TABLE 1 Design Validation and Routine Test Classifications
Design
4. Classification
Test Routine Test
Validation Test
4.1 CFC is furnished in grades, either, standard designated
Tensile Test X X
Glass Transition Temperature X X
CFC1, high strength designated CFC2, or extra high strength
Density X X
designated as CFC3 as specified, in conformance with the
Dimensions X X
requirements of Sections 9–19, and meets the minimum
Heat Exposure X
Heat/Stress Test X
requirements shown in Table 2. (see Explanatory Note 1).
Bending Test X
Dye Penetrant after Bending Test X
5. Ordering Information Tensile Test after Bending Test X
Galvanic Protection Barrier Layer XX
5.1 Orders for material under this specification shall include
Thickness Test
the following information:
5.1.1 Quantity and lengths of each size,
5.1.2 CFC diameter in inches or millimeters (Section 12),
8.2 Design Validation Tests:
5.1.3 Grade (either standard strength, high strength, or extra
8.2.1 The manufacturer shall provide to the purchaser test
high strength),
reports that support the CFC meets the requirements in these
5.1.4 Certification (Section 23),
sections.
5.1.5 Test report, if required (Section 23),
5.1.6 Package type (Section 24), and 8.3 Routine Tests:
B987/B987M−20
A
TABLE 2 Physical Properties (see Explanatory Note 1)
Standard Strength High Strength Extra High Strength
Property
Grade Grade Grade
Ultimate Tensile 250 ksi (1724 MPa) 310 ksi (2137 MPa) 375 ksi (2586 MPa)
Strength, min
Thermoset Polymer 355°F [180°C] to 482°F [250°C] 355°F [180°C] to 482°F [250°C] 355°F [180°C] to 482°F [250°C]
Matrix T ,min
g
Galvanic Layer 0.015 in. 0.015 in. 0.015 in.
Thickness, min [0.38 mm] [0.38 mm] [0.38 mm]
Heat Exposure 95 % retention of rated tensile 95 % retention of rated tensile 95 % retention of rated tensile
Capacity, min strength after 52 weeks of strength after 52 weeks of strength after 52 weeks of
heat exposure heat exposure heat exposure
Bending Diameter, min 100 times diameter of CFC 50 times diameter of CFC 60 times diameter of CFC
B
Tensile Modulus 16.2 Msi 16.2 Msi 21.2 Msi
(111.7 GPa) (111.7 GPa) (146 GPa)
Thermal Expansion Coefficient manufacturer’s nominal value ±5 % manufacturer’s nominal value ±5 % manufacturer’s nominal value ±5 %
Density at 20°C manufacturer’s nominal value ±5 % manufacturer’s nominal value ±5 % manufacturer’s nominal value ±5 %
Maximum continuous heat exposure capability temperature heat exposure capability temperature heat exposure capability temperature
operating temperature temperature minus 35°F [20°C] temperature minus 35°F [20°C] temperature minus 35°F [20°C]
A
Properties listed are before stranding values.
B
For informational purposes only; see manufacturer for specific values.
8.3.1 The manufacturer shall test each production lot using 10. Glass Transition Temperature (T ) Test
g
samples of core of sufficient length to run all testing and
10.1 The glass transition temperature (T ) shall be deter-
g
potential retests. The samples shall be taken from the start and
mined in accordance with Test Method D7028.
end of the lot. Specimens from each sample shall be subjected
10.2 The CFC DMA specimen shall be machined into a
to the required testing.
rectangular shape that meets the requirements described inTest
8.3.2 Upon request from purchaser, the manufacturer shall
Method D7028.
provide test reports that support the CFC meets the require-
ments in these sections. 10.3 Prior to measurement in the DMA, the specimens shall
be preconditioned in accordance with Test Method D7028 to
8.4 Retesting:
determine the dry T of the CFC. If the test specimen is within
g
8.4.1 Should one or more of the test specimens from the
2 weeks of the date of manufacture, the preconditioning may
sample fail any of the tests specified, the nonconforming lot
be reduced to 24 h at 221°F [105°C]. The specimen should be
may be subjected to retesting (see Explanatory Note 3).
kept in a desiccator after preconditioning until testing, in
8.4.2 For retest purposes, three (3) additional specimens
accordance with Test Method D7028.
may be cut from the original samples from the nonconforming
10.4 The peak in the loss modulus shall be used to deter-
lot and tested for the property in which the original specimen
mine the T (see Explanatory Note 5). The T value shall meet
g g
from the lot failed to comply. Retests shall be performed using
the requirements in Table 2.
the area (start or end) of the lot that failed.
8.4.3 Should any of the retest specimens fail to meet the
11. Density
property specified, the lot represented by the test specimen
11.1 For the purpose of calculating mass per unit length,
shal
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
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.
´1
Designation: B987/B987M − 17 B987/B987M − 20
Standard Specification for
Carbon Fiber Thermoset Polymer Matrix Composite Core
(CFC) for use in Overhead Electrical Conductors
This standard is issued under the fixed designation B987/B987M; 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.
ε NOTE—Table 2 was corrected editorially in November 2017.
1. Scope
1.1 This specification covers carbon fiber reinforced thermoset matrix composite core strength members for use in reinforcing
or supporting overhead electrical conductors.
1.2 This specification covers carbon fiber core diameters from 0.180 to 0.500 in. [4.57 to 12.7 mm], inclusive.
1.3 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 non-conformance with the standard.
1.4 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, health, and environmental practices and determine the applicability of
regulatory limitations prior to use.
1.5 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 The following documents of the issue in effect on date of material purchase form a part of this specification to the extent
referenced herein.
2.2 ASTM Standards:
D792 Test Methods for Density and Specific Gravity (Relative Density) of Plastics by Displacement
D3916 Test Method for Tensile Properties of Pultruded Glass-Fiber-Reinforced Plastic Rod
D5117 Test Method for Dye Penetration of Solid Fiberglass Reinforced Pultruded Stock
D5423 Specification for Forced-Convection Laboratory Ovens for Evaluation of Electrical Insulation
D7028 Test Method for Glass Transition Temperature (DMA Tg) of Polymer Matrix Composites by Dynamic Mechanical
Analysis (DMA)
E29 Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications
3. Terminology
3.1 Definitions of Terms Specific to This Standard:
3.1.1 CFC (carbon fiber composite core/thermoset matrix), n—consisting of continuous carbon fiber tows held together by a
polymer matrix where the polymer is specifically a thermosetting polymer. The carbon fiber composite core is protected with a
galvanic protection barrier layer.
3.1.2 core, n—see CFC.
This specification is under the jurisdiction of ASTM Committee B01 on Electrical Conductors and is the direct responsibility of Subcommittee B01.07 on Conductors
of Light Metals.
Current edition approved Feb. 1, 2017Aug. 1, 2020. Published March 2017August 2020. Originally approved in 2014. Last previous edition approved in 20142017 as
ɛ1
B987/B987MB987/B987M – 17 – 14. DOI: 10.1520/B0987/B0987M-17E01. DOI: 10.1520/B0987_B0987M-20.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
B987/B987M − 20
3.1.3 design validation tests, n—the purpose of these tests is to verify the suitability of the CFC design, materials, and method
of manufacturing to meet the requirements in this specification. To ensure compliance with this specification, these tests shall be
performed on composite core samples at the time of manufacture and be repeated whenever the design, manufacturing method or
the materials have changed. The results of design validation tests are to be recorded and are considered valid for the whole class
of CFC.
3.1.4 DMA (dynamic mechanical analyzer), n—a device that measures the T of a polymer matrix or composite by subjecting
g
the sample to an oscillating stress while heating the specimen at a given heating rate.
3.1.5 galvanic protection barrier layer, n—a non-conductive layer that prevents the carbon fiber of the composite core from
making contact with the aluminum strands used in the conductor.
3.1.6 glass transition temperature (T ), n—a temperature where the polymer matrix properties transition from a hard, glassy
g
state to a rubbery state. This temperature is defined to be the temperature at which a curve defined by plotting loss modulus versus
temperature reaches its peak value.
3.1.7 loss modulus, n—represents the viscous portion of the polymer matrix response to the simultaneous application of heat
and stress; is proportional to the energy dissipated as heat by the composite sample in the DMA and reaches a maximum value
when the polymer matrix in the composite transitions from the glassy to the rubbery state (T ).
g
3.1.8 lot, n—unless otherwise specified in the contract or order, a lot shall consist of all coils of CFC of the same diameter,
produced from one continuous run of a fiber setup, submitted for inspection at the same time.
3.1.9 matrix volume fraction, n—the amount of matrix resin relative to fiber in a composite core. The matrix volume fraction
is calculated by subtracting the area of the glass and carbon fibers from the total area of the part and then dividing by the total area
of the part.
3.1.10 polymer matrix, n—a high molecular weight organic material consisting of repeating chemical structures.
3.1.11 production unit, n—a reel, spool, or other package of CFC that represents a single usable length.
3.1.12 routine tests, n—tests that are performed by the manufacturer, and are intended to prove conformance to the specific
requirements.
3.1.13 sample, n—a length of composite core removed from the start or end of a CFC lot, and considered to have properties
representative of the lot.
3.1.14 specimen, n—a length of composite core taken from a lot of CFC for testing purposes.
3.1.15 tow, n—a bundle, containing multiple fibers. Tow sizes range from 1 K (1000 fibers per bundle) to 50 K (50 000 fibers
per bundle).
3.1.16 rated T —the minimum T value guaranteed by the supplier of the CFC.
g g
3.2 Product Code—Defines the strength grade for product produced to this specification: Standard Strength (Code CFC1); High
Strength (Code CFC2); and Extra High Strength (Code CFC3).
4. Classification
4.1 CFC is furnished in grades, either, standard designated CFC1, high strength designated CFC2, or extra high strength
designated as CFC3 as specified, in conformance with the requirements of Sections 9 – 19, and meets the minimum requirements
shown in Table 2. (see Explanatory Note 1).
5. Ordering Information
5.1 Orders for material under this specification shall include the following information:
5.1.1 Quantity and lengths of each size,
5.1.2 CFC diameter in inches or millimeters (Section 12),
5.1.3 Grade (either standard strength, high strength, or extra high strength),
5.1.4 Certification (Section 23),
5.1.5 Test report, if required (Section 23),
5.1.6 Package type (Section 24), and
5.1.7 Order example: Five (5) lengths of 24 000 ft [7300 m] each, 0.375 in. [9.53 mm] CFC, high strength grade, packaged onto
wood nonreturnable reels, with certified test report.
6. Materials and Manufacture
6.1 The CFC shall consist of carbon fibers of suitable type that are combined with a suitable heat resistant thermoset polymer
matrix, and encased in a galvanic protection barrier layer.
6.1.1 The galvanic protection barrier shall meet the requirements set forth in this specification including thickness, minimum
bending diameter, and dye penetrant after bending.
B987/B987M − 20
6.2 The CFC shall meet the requirements set forth in this specification, including tensile strength, glass transition temperature
(T ) and minimum bending diameter.
g
7. Classes of CFC
7.1 The classes of CFC products shall be designated by the individual manufacturer and are designs that meet the specified
strength grade, and are further defined as having cores with the following properties:
7.1.1 Meet the specified grade of strength.
7.1.2 The area ratio of carbon fiber plus matrix resin to galvanic protection layer is held within 610 %.
7.1.3 The nominal matrix volume fraction is held within 63 % in a given strength grade of CFC.
7.1.4 Use the same thermoset polymer matrix resin (including any fillers that are added to the polymer matrix) and same
galvanic protection system (including any fillers).
7.1.5 Have a core diameter within 615 % of the baseline diameter used for design validation tests (see Explanatory Note 2).
8. Test Classifications and Number of Tests and Retests
8.1 Test requirements are classified as either design validation tests or routine tests as indicated in Table 1.
TABLE 1 Design Validation and Routine Test Classifications
Design
Test Routine Test
Validation Test
Tensile Test X X
Glass Transition Temperature X X
Density X X
Dimensions X X
Heat Exposure X
Heat/Stress Test X
Bending Test X
Dye Penetrant after Bending Test X
Tensile Test after Bending Test X
Galvanic Protection Barrier Layer X X
Thickness Test
8.2 Design Validation Tests:
8.2.1 The manufacturer shall provide to the purchaser test reports that support the CFC meets the requirements in these sections.
A
TABLE 2 Physical Properties (see Explanatory Note 1)
Standard Strength High Strength Extra High Strength
Property
Grade Grade Grade
Ultimate Tensile 250 ksi (1724 MPa) 310 ksi (2137 MPa) 375 ksi (2586 MPa)
Strength, min
Thermoset Polymer 355°F [180°C] to 482°F [250°C] 355°F [180°C] to 482°F [250°C] 355°F [180°C] to 482°F [250°C]
Matrix T , min
g
Galvanic Layer 0.015 in. 0.015 in. 0.015 in.
Thickness, min [0.38 mm] † [0.38 mm] † [0.38 mm] †
Galvanic Layer 0.015 in. 0.015 in. 0.015 in.
Thickness, min [0.38 mm] [0.38 mm] [0.38 mm]
Heat Exposure 95 % retention of rated tensile 95 % retention of rated tensile 95 % retention of rated tensile
Capacity, min strength after 52 weeks of strength after 52 weeks of strength after 52 weeks of
heat exposure heat exposure heat exposure
Bending Diameter, min 100 times diameter of CFC 50 times diameter of CFC 60 times diameter of CFC
B
Tensile Modulus 16.2 Msi 16.2 Msi 21.2 Msi
(111.7 GPa) (111.7 GPa) (146 GPa)
Thermal Expansion Coefficient manufacturer’s nominal value ±5 % manufacturer’s nominal value ±5 % manufacturer’s nominal value ±5 %
Density at 20°C manufacturer’s nominal value ±5 % manufacturer’s nominal value ±5 % manufacturer’s nominal value ±5 %
Maximum continuous heat exposure capability temperature heat exposure capability temperature heat exposure capability temperature
operating temperature temperature minus 35°F [20°C] temperature minus 35°F [20°C] temperature minus 35°F [20°C]
A
Properties listed are before stranding values.
B
For informational purposes only; see manufacturer for specific values.
† Corrected editorially.
B987/B987M − 20
8.3 Routine Tests:
8.3.1 The manufacturer shall test each production lot using samples of core of sufficient length to run all testing and potential
retests. The samples shall be taken from the start and end of the lot. Specimens from each sample shall be subjected to the required
testing.
8.3.2 Upon request from purchaser, the manufacturer shall provide test reports that support the CFC meets the requirements in
these sections.
8.4 Retesting:
8.4.1 Should one or more of the test specimens from the sample fail any of the tests specified, the nonconforming lot may be
subjected to retesting (see Explanatory Note 3).
8.4.2 For retest purposes, three (3) additional specimens may be cut from the original samples from the nonconforming lot and
tested for the property in which the original specimen from the lot failed to comply. Retests shall be performed using the area (start
or end) of the lot that failed.
8.4.3 Should any of the retest specimens fail to meet the property specified, the lot represented by the test specimen shall be
rejected.
9. Tensile Test
9.1 The CFC shall conform to the tensile strength requirements prescribed in Table 2.
9.2 Tensile tests on the finished CFC shall be conducted in accordance with the test methods and definitions section of Test
Method D3916 (see Explanatory Note 4).
9.3 Calculation of tensile properties shall be based on the total cross sectional area of the core including the galvanic protection
layer.
10. Glass Transition Temperature (T ) Test
g
10.1 The glass transition temperature (T ) shall be determined in accordance with Test Method D7028.
g
10.2 The CFC DMA specimen shall be machined into a rectangular shape that meets the requirements described in Test Method
D7028.
10.
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