ASTM D5041-98(2004)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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: D5041 – 98 (Reapproved 2004)
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. Terminology
1.1 This test method covers the determination of fracture 3.1 Definitions—Many of the terms used in this test method
strengthincleavageofadhesivebondswhentestedonstandard are defined in Terminology D907.
reinforced plastic specimens and under specified conditions of 3.2 Definitions of Terms Specific to This Standard:
preparation and testing (Note 1). 3.2.1 failure initiation energy, E—the area under the load
i
deflection curve where the first significant load drop occurs
NOTE 1—Whilethistestmethodisintendedforuseinreinforcedplastic
after the start of the test, showing the onset of permanent
applications, it may be used for measuring fracture properties of adhesives
damage to the bonded assembly (see Fig. 1).
using other plastic adherends, provided consideration is given to the
thickness and should be of equal rigidity to the plastic adherends. 3.2.2 failure propagation energy, E —the area under the
p
load-deflection curve beginning at the failure initiation energy
1.2 The values stated in SI units are to be regarded as the
and ending at the catastrophic failure of the bonded assembly.
standard. The values given in parentheses are for information
(See Fig. 1).
only.
3.2.3 semirigid—indicates that the adherends shall have
1.3 This standard does not purport to address all of the
such dimensions and physical properties as to permit bending
safety concerns, if any, associated with its use. It is the
them through any angle of up to 30° without breaking or
responsibility of the user of this standard to establish appro-
cracking.
priate safety and health practices and determine the applica-
3.2.4 semirigid adherend, n—an adherend that has dimen-
bility of regulatory limitations prior to use.
sions and physical properties that permit bending at designated
2. Referenced Documents test temperature through any angle up to 30° without breaking
2 or cracking.
2.1 ASTM Standards:
3.2.5 total energy—failure initiation energy plus failure
D618 Practice for Conditioning Plastics for Testing
propagation energy.
D907 Terminology of Adhesives
D2093 Practice for Preparation of Surfaces of Plastics Prior
4. Significance and Use
to Adhesive Bonding
4.1 This test method provides a means of measuring the
D5573 Practice for Classifying Failure Modes in Fiber-
cleavageforcesandenergiesrequiredtofailadhesivelybonded
Reinforced-Plastic (FRP) Joints
reinforced flat bonded specimens. It also offers a semi-
E4 Practices for Force Verification of Testing Machines
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.
distinguishing differences between adhesives.
Current edition approved April 1, 2004. Published April 2004. Originally
approved in 1990. Last previous edition approved in 1998 as D5041 – 98. DOI: 4.3 It is important to note that the test method measures
10.1520/D5041-98R04.
performance properties of the total bonded system (for ex-
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
ample, reinforced plastic and adhesive) but will not yield
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
fundamental properties of the adhesive alone.
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.
D5041 – 98 (2004)
FIG. 2 Wedge with Removable Tip
FIG. 1 A 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
mechanism is to be essentially free from inertia-lag at the
FIG. 3 Test Setup
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 5.6 Bond Fixture, any suitable fixture with temperature- and
pressure-controlled platens, capable of bonding test assemblies
in accordance with Practices E4.
5.2 Wedge, made of either aluminum or steel with an in accordance with the adhesive manufacturer’s recommenda-
tions.
included angle of 45°. The sides of the wedge are machined
smooth with the edge having a radius not to exceed 0.02 mm
6. Test Assemblies
(0.01 in).
6.1 Flat Adherend, unless otherwise specified in material
NOTE 2—A stainless steel wedge is recommended, has been found to
specifications, make the test adherends in conformance to the
work well, and is very durable. Due to the weight of a steel wedge, the
form and dimensions shown in Fig. 4. Cut them from flat
removal of excess metal, which does not adversely affect the stiffness of
the wedge, is recommended. semirigid plastic panels having a nominal thickness of 2.54
mm (0.1 in.) 6 0.5 %. Cut adherends into sections, 150 by 150
5.3 Removable Tip (Optional)—In some cases, the tip of the
mm (6 by 6 in.), 6 0.5 %. (See appendix for optional specimen
traveling wedge will strike the adhesive before catastrophic
sizes.)
failure. This phenomenon will lead to grossly distorted test
data. Should this be a problem in some adhesively bonded
7. Preparation
assemblies, a removable tip wedge of the design shown in Fig.
7.1 Laminated test assemblies (Fig. 5) consist of two
2 is suggested.
adherends of similar stiffness properly prepared and bonded
5.4 Support Fixture, an adjustable fixture used to support
together.
andcenterthebondedassemblyunderthetipofthewedge.See
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.)
D5041 – 98 (2004)
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 cur-
ing, remove the shims from the bonded assemblies and trim the
adhesivesqueeze-out.Allowthebondedassembliestocooland
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.
FIG. 4 Placement of Adhesive Bead 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
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
...