ASTM D5041-98(2019)

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:D5041 −98 (Reapproved 2019)
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 E4 Practices for Force Verification of Testing Machines
1.1 This test method covers the determination of fracture
3. Terminology
strengthincleavageofadhesivebondswhentestedonstandard
reinforced plastic specimens and under specified conditions of
3.1 Definitions—Many of the terms used in this test method
preparation and testing (Note 1).
are defined in Terminology D907.
NOTE 1—While this test method is intended for use in reinforced plastic
3.2 Definitions of Terms Specific to This Standard:
applications, it may be used for measuring fracture properties of adhesives
3.2.1 failure initiation energy, E—the area under the load
using other plastic adherends, provided consideration is given to the i
deflection curve where the first significant load drop occurs
thickness and should be of equal rigidity to the plastic adherends.
after the start of the test, showing the onset of permanent
1.2 The values stated in SI units are to be regarded as the
damage to the bonded assembly (see Fig. 1).
standard. The values given in parentheses are for information
only.
3.2.2 failure propagation energy, E —the area under the
p
load-deflection curve beginning at the failure initiation energy
1.3 This standard does not purport to address all of the
and ending at the catastrophic failure of the bonded assembly.
safety concerns, if any, associated with its use. It is the
(See Fig. 1).
responsibility of the user of this standard to establish appro-
priate safety, health, and environmental practices and deter-
3.2.3 semirigid—indicates that the adherends shall have
mine the applicability of regulatory limitations prior to use.
such dimensions and physical properties as to permit bending
1.4 This international standard was developed in accor-
them through any angle of up to 30° without breaking or
dance with internationally recognized principles on standard-
cracking.
ization established in the Decision on Principles for the
3.2.4 semirigid adherend, n—an adherend that has dimen-
Development of International Standards, Guides and Recom-
sions and physical properties that permit bending at designated
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee. test temperature through any angle up to 30° without breaking
or cracking.
2. Referenced Documents
3.2.5 total energy—failure initiation energy plus failure
2.1 ASTM Standards:
propagation energy.
D618 Practice for Conditioning Plastics for Testing
D907 Terminology of Adhesives
4. Significance and Use
D2093 Practice for Preparation of Surfaces of Plastics Prior
4.1 This test method provides a means of measuring the
to Adhesive Bonding
cleavageforcesandenergiesrequiredtofailadhesivelybonded
D5573 Practice for Classifying Failure Modes in Fiber-
reinforced flat bonded specimens. It also offers a semi-
Reinforced-Plastic (FRP) Joints
quantitative observation of failure mode.
4.2 This test method has found application in screening
This test method is under the jurisdiction of ASTM Committee D14 on
structural adhesives for bonding reinforced plastics where
AdhesivesandisthedirectresponsibilityofSubcommitteeD14.40onAdhesivesfor
simple lap shear testing has proven to be inadequate in
Plastics.
Current edition approved June 1, 2019. Published June 2019. Originally
distinguishing differences between adhesives.
approved in 1990. Last previous edition approved in 2012 as D5041 – 98 (2012).
DOI: 10.1520/D5041-98R19.
4.3 It is important to note that the test method measures
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
performance properties of the total bonded system (for
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
example, reinforced plastic and adhesive) but will not yield
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. fundamental properties of the adhesive alone.
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D5041−98 (2019)
FIG. 2Wedge with Removable Tip
FIG. 1A Typical Load versus Deflection Curve for Wedge Test
5. Apparatus
5.1 Testing Machine, any suitable testing machine capable
of control of constant-rate-of-crosshead movement and com-
prising essentially the following:
5.1.1 Drive Mechanism, a mechanism for imparting to the
cross-head movable member, a uniform, controlled velocity
with respect to the base (fixed member); this velocity is to be
regulated as specified in Section 10.
5.1.2 Load Indicator, a mechanism capable of showing the
total compressive load carried by the test specimen. The
FIG. 3Test Setup
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).
5.5 Integrator, a mechanical or electronic device or com-
Verify the accuracy of the testing machine at least once a year
puter for the determination of failure energies.
in accordance with Practices E4.
5.6 Bond Fixture, any suitable fixture with temperature- and
5.2 Wedge, made of either aluminum or steel with an
pressure-controlled platens, capable of bonding test assemblies
included angle of 45°. The sides of the wedge are machined
in accordance with the adhesive manufacturer’s recommenda-
smooth with the edge having a radius not to exceed 0.02 mm
tions.
(0.01 in).
6. Test Assemblies
NOTE 2—A stainless steel wedge is recommended, has been found to
work well, and is very durable. Due to the weight of a steel wedge, the
6.1 Flat Adherend, unless otherwise specified in material
removal of excess metal, which does not adversely affect the stiffness of
specifications, make the test adherends in conformance to the
the wedge, is recommended.
form and dimensions shown in Fig. 4. Cut them from flat
5.3 Removable Tip (Optional)—In some cases, the tip of the
semirigid plastic panels having a nominal thickness of 2.54
traveling wedge will strike the adhesive before catastrophic
mm (0.1 in.) 60.5 %. Cut adherends into sections, 150 by 150
failure. This phenomenon will lead to grossly distorted test
mm (6 by 6 in.), 60.5 %. (See appendix for optional specimen
data. Should this be a problem in some adhesively bonded
sizes.)
assemblies, a removable tip wedge of the design shown in Fig.
2 is suggested. 7. Preparation
5.4 Support Fixture, an adjustable fixture used to support 7.1 Laminated test assemblies (Fig. 5) consist of two
andcenterthebondedassemblyunderthetipofthewedge.See adherends of similar stiffness properly prepared and bonded
Fig. 3. together.
D5041−98 (2019)
TFE-fluorocarbon or release coated steel shim, as shown, to
control final adhesive thickness.
7.5 Mate the two halves of the cleavage assembly as soon as
possible after applying the glass beads to form the test
assembly shown in Fig. 5. The entire bonded assembly may be
wrapped in aluminum foil to protect the heated platens used to
cure the adhesive. Cure the adhesive in accordance with the
adhesive suppliers’ recommendation. Immediately after
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
FIG. 4Placement of Adhesive Bead
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
2°C(73.4 63.6°F)and50 65 %relativehumidityfornotless
than 14 h prior to test in accordance with Procedure A of
Practice D618 for those tests where conditioning
...