ASTM D5041-98

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: D 5041 – 98
Standard Test Method for
Fracture Strength in Cleavage of Adhesives in Bonded
Joints
This standard is issued under the fixed designation D 5041; 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 (e) 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
strength in cleavage of adhesive bonds when tested on standard
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
p
preparation and testing (Note 1).
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
3.2.3 semirigid—indicates that the adherends shall have
thickness and should be of equal rigidity to the plastic adherends.
such dimensions and physical properties as to permit bending
1.2 The values stated in SI units are to be regarded as the
them through any angle of up to 30° without breaking or
standard. The values given in parentheses are for information
cracking.
only.
3.2.4 semirigid adherend, n—an adherend that has dimen-
1.3 This standard does not purport to address all of the
sions and physical properties that permit bending at designated
safety concerns, if any, associated with its use. It is the
test temperature through any angle up to 30° without breaking
responsibility of the user of this standard to establish appro-
or cracking.
priate safety and health practices and determine the applica-
3.2.5 total energy—failure initiation energy plus failure
bility of regulatory limitations prior to use.
propagation energy.
2. Referenced Documents
4. Significance and Use
2.1 ASTM Standards:
4.1 This test method provides a means of measuring the
D 618 Practice for Conditioning Plastics and Electrical
cleavage forces and energies required to fail adhesively bonded
Insulating Materials for Testing
reinforced flat bonded specimens. It also offers a semi-
D 907 Terminology of Adhesives
quantitative observation of failure mode.
D 2093 Practice for Preparation of Surfaces of Plastics Prior
4.2 This test method has found application in screening
to Adhesive Bonding
structural adhesives for bonding reinforced plastics where
D 5573 Practice for Classifying Failure Modes in Fiber-
simple lap shear testing has proven to be inadequate in
Reinforced-Plastic (FRP) Joints
distinguishing differences between adhesives.
E 4 Practices for Force Verification of Testing Machines
4.3 It is important to note that the test method measures
performance properties of the total bonded system (for ex-
3. Terminology
ample, reinforced plastic and adhesive) but will not yield
3.1 Definitions—Many of the terms used in this test method
fundamental properties of the adhesive alone.
are defined in Terminology D 907.
3.2 Definitions of Terms Specific to This Standard:
5. Apparatus
5.1 Testing Machine, any suitable testing machine capable
1 of control of constant-rate-of-crosshead movement and com-
This test method is under the jurisdiction of ASTM Committee D-14 on
prising essentially the following:
Adhesives and is the direct responsibility of Subcommittee D14.40 on Adhesives for
Plastics.
5.1.1 Drive Mechanism, a mechanism for imparting to the
Current edition approved March 10, 1998. Published February 1999. Originally
cross-head movable member, a uniform, controlled velocity
published as D 5041 – 90. Last previous edition D 5041 – 93b.
with respect to the base (fixed member); this velocity is to be
Annual Book of ASTM Standards, Vol 08.01.
Annual Book of ASTM Standards, Vol 15.06. regulated as specified in Section 10.
Annual Book of ASTM Standards, Vol 03.01.
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D5041–98
FIG. 2 Wedge with Removable Tip
FIG. 1 A 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
of6 1 % 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 E 4.
5.2 Wedge, made of either aluminum or steel with an
included angle of 45°. The sides of the wedge are machined
smooth with the edge having a radius not to exceed 0.02 mm
(0.01 in).
FIG. 3 Test Setup
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
removal of excess metal, which does not adversely affect the stiffness of
form and dimensions shown in Fig. 4. Cut them from flat
the wedge, is recommended.
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.) 6 0.5 %. Cut adherends into sections, 150 by 150
traveling wedge will strike the adhesive before catastrophic mm (6 by 6 in.), 6 0.5 %. (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
and center the bonded assembly under the tip of the wedge. 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.
6. Test Assemblies
NOTE 4—It is important to be aware of potential substrate surface
6.1 Flat Adherend, unless otherwise specified in material
differences. Frequently reinforced plastics have a preferred bonding side.
specifications, make the test adherends in conformance to the Contact the substrate supplier if there is any doubt.
D5041–98
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
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
Practices D 618 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-
FIG. 4 Placement of Adhesive Bead
tory atmosphere of 23 6 2°C (73.4 6 3.6°F) and 50 6 5%
relative humidity, unless
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