ASTM D7078/D7078M-05
(Test Method)Standard Test Method for Shear Properties of Composite Materials by V-Notched Rail Shear Method
Standard Test Method for Shear Properties of Composite Materials by V-Notched Rail Shear Method
SIGNIFICANCE AND USE
This shear test is designed to produce shear property data for material specifications, research and development, quality assurance, and structural design and analysis. Either in-plane or interlaminar shear properties may be evaluated, depending upon the orientation of the material coordinate system relative to the loading axis. Factors that influence the shear response and should therefore be reported include: material, methods of material preparation and lay-up, specimen stacking sequence, specimen preparation, specimen conditioning, environment of testing, specimen alignment and gripping, speed of testing, time at temperature, void content, and volume percent reinforcement.
In anisotropic materials, properties may be obtained in any of the six possible shear planes by orienting the testing plane of the specimen with the desired material plane (1-2 or 2-1, 1-3 or 3-1, 2-3 or 3-2). Only a single shear plane may be evaluated for any given specimen. Properties, in the test direction, which may be obtained from this test method, include the following:
5.2.1 Shear stress versus engineering shear strain response,
5.2.2 Ultimate shear strength,
5.2.3 Ultimate engineering shear strain,
5.2.4 Shear chord modulus of elasticity,
5.2.5 Transition strain.
SCOPE
1.1 This test method covers the determination of the shear properties of high-modulus fiber-reinforced composite materials by clamping the ends of a V-notched specimen between two pairs of loading rails. When loaded in tension, the rails introduce shear forces into the specimen through the specimen faces. In comparison, the specimen of Test Method D 5379/D 5379M is loaded through its top and bottom edges. Face loading allows higher shear forces to be applied to the specimen, if required. Additionally, the present test method utilizes a specimen with a larger gage section than the V-notched specimen of Test Method D 5379/D 5379M. In both test methods, the use of a V-notched specimen increases the gage section shear stresses in relation to the shear stresses in the vicinity of the grips, thus localizing the failure within the gage section while causing the shear stress distribution to be more uniform than in a specimen without notches. In comparison, Test Method D 4255/D 4255M utilizes an unnotched specimen clamped between two pairs of loading rails that are loaded in tension. Also in contrast to Test Method D 4255/D 4255M, the present test method provides specimen gripping without the need for holes in the specimen.
The composite materials are limited to continuous-fiber or discontinuous-fiber-reinforced composites in the following material forms:
1.1.1 Laminates composed only of unidirectional fibrous laminae, with the fiber direction oriented either parallel or perpendicular to the fixture rails.
1.1.2 Laminates of balanced and symmetric construction, with the 0 direction oriented either parallel or perpendicular to the fixture rails.
1.1.3 Laminates composed of woven, braided, or knitted fabric filamentary laminae.
1.1.4 Short-fiber-reinforced composites with a majority of the fibers being randomly distributed.
1.2 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.
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 and health practices and determine the applicability of regulatory limitations prior to use.
General Information
Relations
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
Designation: D7078/D7078M − 05
StandardTest Method for
Shear Properties of Composite Materials by V-Notched Rail
1
Shear Method
This standard is issued under the fixed designation D7078/D7078M; 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 inch-pound units are shown in brackets. The values stated in
each system are not exact equivalents; therefore, each system
1.1 This test method covers the determination of the shear
must be used independently of the other. Combining values
properties of high-modulus fiber-reinforced composite materi-
from the two systems may result in nonconformance with the
alsbyclampingtheendsofaV-notchedspecimenbetweentwo
standard.
pairs of loading rails. When loaded in tension, the rails
1.3 This standard does not purport to address all of the
introduce shear forces into the specimen through the specimen
safety concerns, if any, associated with its use. It is the
faces. In comparison, the specimen of Test Method D5379/
responsibility of the user of this standard to establish appro-
D5379M is loaded through its top and bottom edges. Face
priate safety and health practices and determine the applica-
loading allows higher shear forces to be applied to the
bility of regulatory limitations prior to use.
specimen, if required. Additionally, the present test method
utilizes a specimen with a larger gage section than the
2. Referenced Documents
V-notched specimen of Test Method D5379/D5379M. In both
2
test methods, the use of a V-notched specimen increases the
2.1 ASTM Standards:
gage section shear stresses in relation to the shear stresses in
D792Test Methods for Density and Specific Gravity (Rela-
the vicinity of the grips, thus localizing the failure within the
tive Density) of Plastics by Displacement
gage section while causing the shear stress distribution to be
D883Terminology Relating to Plastics
more uniform than in a specimen without notches. In
D2584Test Method for Ignition Loss of Cured Reinforced
comparison, Test Method D4255/D4255M utilizes an un-
Resins
notched specimen clamped between two pairs of loading rails
D2734TestMethodsforVoidContentofReinforcedPlastics
that are loaded in tension. Also in contrast to Test Method
D3171Test Methods for Constituent Content of Composite
D4255/D4255M, the present test method provides specimen
Materials
gripping without the need for holes in the specimen.
D3878Terminology for Composite Materials
The composite materials are limited to continuous-fiber or
D4255/D4255MTest Method for In-Plane Shear Properties
discontinuous-fiber-reinforcedcompositesinthefollowingma-
of Polymer Matrix Composite Materials by the Rail Shear
terial forms:
Method
1.1.1 Laminates composed only of unidirectional fibrous
D5229/D5229MTestMethodforMoistureAbsorptionProp-
laminae, with the fiber direction oriented either parallel or
erties and Equilibrium Conditioning of Polymer Matrix
perpendicular to the fixture rails.
Composite Materials
1.1.2 Laminates of balanced and symmetric construction,
D5379/D5379MTest Method for Shear Properties of Com-
withthe0°directionorientedeitherparallelorperpendicularto
posite Materials by the V-Notched Beam Method
the fixture rails.
D6856Guide for Testing Fabric-Reinforced “Textile” Com-
1.1.3 Laminates composed of woven, braided, or knitted
posite Materials
fabric filamentary laminae.
E4Practices for Force Verification of Testing Machines
1.1.4 Short-fiber-reinforced composites with a majority of
E6Terminology Relating to Methods of Mechanical Testing
the fibers being randomly distributed.
E111Test Method for Young’s Modulus, Tangent Modulus,
and Chord Modulus
1.2 The values stated in either SI units or inch-pound units
E122PracticeforCalculatingSampleSizetoEstimate,With
are to be regarded separately as standard. Within the text the
1
This test method is under the jurisdiction of ASTM Committee D30 on
2
Composite Materials and is the direct responsibility of Subcommittee D30.04 on For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Lamina and Laminate Test Methods. contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Current edition approved May 15, 2005. Published August 2005. DOI: 10.1520/ Standards volume information, refer to the standard’s Document Summary page on
D7078_D7078M-05. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1
---------------------- Page: 1 ----------------------
D7078/D7078M − 05
Specified Precision, the Average for a Characteristic of a
Lot or Process
E177Practice for Use o
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.