ASTM C297-94(1999)

Standard Test Method for Flatwise Tensile Strength of Sandwich Constructions

SCOPE
1.1 This test method covers the determination of the core flatwise tension strength, or the bond between core and facings of an assembled sandwich panel. The test consists of subjecting a sandwich construction to a tensile load normal to the plane of the sandwich, such load being transmitted to the sandwich through thick loading blocks bonded to the sandwich facings or directly to the core.  
1.2 The values stated in SI units are to be regarded as the standard. The inch-pound units given may be approximate.  
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

• Status: Historical
• Publication Date: 09-Jun-1999
• ICS: 83.120 - Reinforced plastics
• Technical Committee: D30 - Composite Materials
• Drafting Committee: D30.09 - Sandwich Construction

Relations

• Replaced By: ASTM C297/C297M-04 - Standard Test Method for Flatwise Tensile Strength of Sandwich Constructions
• Effective Date: 01-May-2004

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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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: C 297 – 94 (Reapproved 1999)
Standard Test Method for
Flatwise Tensile Strength of Sandwich Constructions
This standard is issued under the fixed designation C 297; 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.
This standard has been approved for use by agencies of the Department of Defense.
1. Scope of apparatus is shown in Fig. 1. The loading blocks shall be
sufficiently stiff to keep the bonded facings essentially flat
1.1 This test method covers the determination of the core
under load. Loading blocks 40 to 50 mm (1.5 to 2.0 in.) thick
flatwise tension strength or the bond between core and facings
have been found to perform satisfactorily.
of an assembled sandwich panel. The test consists of subjecting
4.3 Micrometer, gage, or caliper, capable of measuring
a sandwich construction to a tensile load normal to the plane of
accurately to 0.025 mm (0.001 in.).
the sandwich, such load being transmitted to the sandwich
through thick loading blocks bonded to the sandwich facings or
5. Test Specimens
directly to the core.
5.1 Test specimens shall be square or round and equal in
1.2 The values stated in SI units are to be regarded as the
thickness to the sandwich panel thickness. All dimensions shall
standard. The inch-pound units given may be approximate.
be measured to the nearest 0.25 mm (0.01 in.). Minimum areas
1.3 This standard does not purport to address all of the
for various types of core materials are given below:
safety concerns, if any, associated with its use. It is the
5.1.1 For continuous cores, such as balsa wood and foams,
responsibility of the user of this standard to establish appro-
the minimum facing area of the specimen shall be 625 mm (1
priate safety and health practices and determine the applica-
in. ).
bility of regulatory limitations prior to use.
5.1.2 For open-celled cores, such as honeycomb, having
2. Referenced Documents cells less than 6 mm (0.5 in.), the minimum area shall be 2600
2 2
mm (4 in. ), and for cells 6 mm (0.5 in.) or greater, the
2.1 ASTM Standards:
2 2
minimum area shall be 5800 mm (9 in. ).
E 4 Practices for Force Verification of Testing Machines
5.2 The loading blocks shall be bonded to the facings of the
3. Significance and Use
test specimen using a suitable adhesive. Ideally, the bonding
temperature and pressure shall not appreciably affect the
3.1 For a sandwich panel to function properly, the facings
existing bond between facing and core. The bonding pressure
must have a sufficient bond to the core.
shall not be greater than the original facing to core bonding
3.2 This test method provides information on how well the
pressure. If possible, the assembly temperature shall be room
facings are bonded to the core or the flatwise tensile strength of
temperature or at least 28°C (50°F) lower than that at which the
the core. It is mainly used as a quality control test for bonded
sandwich was originally bonded.
sandwich panels.
5.3 The number of test specimens and the method of their
4. Apparatus
selection depend on the purpose of the particular test under
consideration, and no general rule can be given to cover all
4.1 Test machine, capable of maintaining a controlled load-
cases. However, when specimens are to be used for acceptance
ing rate and indicating the load with an accuracy of 61% of
tests, at least five specimens shall be tested.
the indicated value. The accuracy of the test machine shall be
verified in accordance with Practices E 4.
6. Conditioning
4.2 Loading fixtures, the loading fixtures shall be self-
6.1 When the physical properties of the component materi-
aligning and shall not apply eccentric loads. A satisfactory type
als are affected by moisture, bring the test specimens to
constant weight (61 %) before testing, preferably in a condi-
This test method is under the jurisdiction of ASTM Committee D-30 on
tioning room with temperature and humidity control, and make
Composite Materials and is the direct responsibility of Subcommittee D30.09 on
the tests, preferably, in
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