ASTM D5041-98(2012)
(Test Method)Standard Test Method for Fracture Strength in Cleavage of Adhesives in Bonded Joints
Standard Test Method for Fracture Strength in Cleavage of Adhesives in Bonded Joints
SIGNIFICANCE AND USE
This test method provides a means of measuring the cleavage forces and energies required to fail adhesively bonded reinforced flat bonded specimens. It also offers a semi-quantitative observation of failure mode.
This test method has found application in screening structural adhesives for bonding reinforced plastics where simple lap shear testing has proven to be inadequate in distinguishing differences between adhesives.
It is important to note that the test method measures performance properties of the total bonded system (for example, reinforced plastic and adhesive) but will not yield fundamental properties of the adhesive alone.
SCOPE
1.1 This test method covers the determination of fracture strength in cleavage of adhesive bonds when tested on standard reinforced plastic specimens and under specified conditions of preparation and testing (Note 1).
Note 1—While this test method is intended for use in reinforced plastic applications, it may be used for measuring fracture properties of adhesives using other plastic adherends, provided consideration is given to the thickness and should be of equal rigidity to the plastic adherends.
1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
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
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Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation:D5041 −98 (Reapproved 2012)
Standard Test Method for
Fracture Strength in Cleavage of Adhesives in Bonded
Joints
This standard is issued under the fixed designation D5041; 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 3.2.1 failure initiation energy, E—the area under the load
i
deflection curve where the first significant load drop occurs
1.1 This test method covers the determination of fracture
after the start of the test, showing the onset of permanent
strengthincleavageofadhesivebondswhentestedonstandard
damage to the bonded assembly (see Fig. 1).
reinforced plastic specimens and under specified conditions of
3.2.2 failure propagation energy, E —the area under the
preparation and testing (Note 1).
p
load-deflection curve beginning at the failure initiation energy
NOTE 1—While this test method is intended for use in reinforced plastic
and ending at the catastrophic failure of the bonded assembly.
applications, it may be used for measuring fracture properties of adhesives
(See Fig. 1).
using other plastic adherends, provided consideration is given to the
thickness and should be of equal rigidity to the plastic adherends.
3.2.3 semirigid—indicates that the adherends shall have
1.2 The values stated in SI units are to be regarded as the such dimensions and physical properties as to permit bending
standard. The values given in parentheses are for information them through any angle of up to 30° without breaking or
only. cracking.
1.3 This standard does not purport to address all of the 3.2.4 semirigid adherend, n—an adherend that has dimen-
safety concerns, if any, associated with its use. It is the sions and physical properties that permit bending at designated
responsibility of the user of this standard to establish appro- test temperature through any angle up to 30° without breaking
priate safety and health practices and determine the applica- or cracking.
bility of regulatory limitations prior to use.
3.2.5 total energy—failure initiation energy plus failure
propagation energy.
2. Referenced Documents
4. Significance and Use
2.1 ASTM Standards:
D618 Practice for Conditioning Plastics for Testing
4.1 This test method provides a means of measuring the
D907 Terminology of Adhesives
cleavageforcesandenergiesrequiredtofailadhesivelybonded
D2093 Practice for Preparation of Surfaces of Plastics Prior
reinforced flat bonded specimens. It also offers a semi-
to Adhesive Bonding
quantitative observation of failure mode.
D5573 Practice for Classifying Failure Modes in Fiber-
4.2 This test method has found application in screening
Reinforced-Plastic (FRP) Joints
structural adhesives for bonding reinforced plastics where
E4 Practices for Force Verification of Testing Machines
simple lap shear testing has proven to be inadequate in
distinguishing differences between adhesives.
3. Terminology
4.3 It is important to note that the test method measures
3.1 Definitions—Many of the terms used in this test method
performance properties of the total bonded system (for
are defined in Terminology D907.
example, reinforced plastic and adhesive) but will not yield
3.2 Definitions of Terms Specific to This Standard:
fundamental properties of the adhesive alone.
5. Apparatus
This test method is under the jurisdiction of ASTM Committee D14 on
AdhesivesandisthedirectresponsibilityofSubcommitteeD14.40onAdhesivesfor
5.1 Testing Machine, any suitable testing machine capable
Plastics.
of control of constant-rate-of-crosshead movement and com-
Current edition approved May 1, 2012. Published May 2012. Originally
prising essentially the following:
approved in 1990. Last previous edition approved in 2004 as D5041 – 98 (2004).
DOI: 10.1520/D5041-98R12.
5.1.1 Drive Mechanism, a mechanism for imparting to the
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
cross-head movable member, a uniform, controlled velocity
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
with respect to the base (fixed member); this velocity is to be
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. regulated as specified in Section 10.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D5041−98 (2012)
FIG. 2Wedge with Removable Tip
FIG. 1A Typical Load versus Deflection Curve for Wedge Test
5.1.2 Load Indicator, a mechanism capable of showing the
total compressive load carried by the test specimen. The
mechanism is to be essentially free from inertia-lag at the
specified rate of testing and indicate the load with an accuracy
of 61 % of the maximum indicated value of the test (load).
Verify the accuracy of the testing machine at least once a year
in accordance with Practices E4.
5.2 Wedge, made of either aluminum or steel with an
included angle of 45°. The sides of the wedge are machined FIG. 3Test Setup
smooth with the edge having a radius not to exceed 0.02 mm
(0.01 in).
6. Test Assemblies
NOTE 2—A stainless steel wedge is recommended, has been found to
6.1 Flat Adherend, unless otherwise specified in material
work well, and is very durable. Due to the weight of a steel wedge, the
specifications, make the test adherends in conformance to the
removal of excess metal, which does not adversely affect the stiffness of
the wedge, is recommended. form and dimensions shown in Fig. 4. Cut them from flat
semirigid plastic panels having a nominal thickness of 2.54
5.3 Removable Tip (Optional)—In some cases, the tip of the
mm (0.1 in.) 60.5 %. Cut adherends into sections, 150 by 150
traveling wedge will strike the adhesive before catastrophic
mm (6 by 6 in.), 60.5 %. (See appendix for optional specimen
failure. This phenomenon will lead to grossly distorted test
sizes.)
data. Should this be a problem in some adhesively bonded
assemblies, a removable tip wedge of the design shown in Fig.
7. Preparation
2 is suggested.
7.1 Laminated test assemblies (Fig. 5) consist of two
5.4 Support Fixture, an adjustable fixture used to support
adherends of similar stiffness properly prepared and bonded
andcenterthebondedassemblyunderthetipofthewedge.See
together.
Fig. 3.
NOTE 3—If the bonded test assembly is constructed with adherends of
5.5 Integrator, a mechanical or electronic device or com-
different stiffness, the result is a peel rather than a cleavage test. (For
puter for the determination of failure energies.
example, higher stiffness promotes cleavage; lower stiffness, peel.)
5.6 Bond Fixture, any suitable fixture with temperature- and 7.2 Prepare the surface of the substrate prior to bonding in
pressure-controlled platens, capable of bonding test assemblies accordance with the adhesive suppliers’ recommendations.
in accordance with the adhesive manufacturer’s recommenda- Typical surface preparations include solvent scrubbing, appli-
tions. cation of primers and, in some cases, only a dry rag wipe.
D5041−98 (2012)
curing, remove the shims from the bonded assemblies and trim
the adhesive squeeze-out.Allow the bonded assemblies to cool
and then condition at 23 6 2°C (73.4 6 3.6°F) for 24 h and 50
6 4 % relative humidity prior to postbaking or testing.
7.6 Postbake assemblies (as required) as experienced in
end-use (production) or in accordance with the adhesive
manufacturer’s recommendation.
8. Number of Test Specimens
8.1 Test at least five specimens for each condition (for
example, adhesive, adherend, or specimen preconditioning).
8.2 Discard specimens that break at some obvious flaw and
make retests, unless such flaws constitute a variable to be
studied.
9. Conditioning
9.1 Conditioning—Condition the test specimens at 23 6
FIG. 4Placement of Adhesive Bead
2°C (73.4 6 3.6°F) and 506 5 % relative humidity for not less
than 14 h prior to test in accordance with Procedure A of
Practice D618 for those tests where conditioning is required. In
cases of disagreement, the tolerances shall be 61°C (61.8°F)
and 62 % relative humidity.
9.2 Test Conditions—Conduct tests in the standard labora-
tory atmosphere of 23 6 2°C (73.4 6 3.6°F) and 50 6 5%
relative humidity, unl
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