ASTM C273 | Sandwich Core Materials | Shear Testing
ASTM C273 is a testing specification that determines the shear properties of sandwich construction core materials associated with shear distortion of planes parallel to the facings. Shear force is applied on a sandwich core or sandwich panel parallel to the plane of its faces. The force is transmitted through the specimen with bonded loading plates. The displacement results in a shear force on the sandwich core. This test method also covers the determination of the shear modulus associated with strains in a plane normal to the facings. Core shear modulus, stress, and strength are reported in terms of the nominal shear area of the core.
This test method provides a standard method of obtaining sandwich core shear data for material specifications, sandwich panel design, research and development, and quality assurance. Before conducting ASTM C273, it is important to read the entire specification in the relevant ASTM publication.
ASTM C273 | Wood and Paper | Shear Testing
Note that there are slight variations depending on the type of sample selected.
- Prepare at least five test specimens as described in the method. The standard specimen thickness should be equal to the thickness of the sandwich, the width should be at least 50 mm (2.0 in), and the length should be at least twelve times the thickness. Measure and record the specimen length, width, and, thickness.
- For this test, either tensile or compressive loading may be used. In both cases, the test specimen should be rigidly supported by means of steel plates bonded to the facings. Bond the specimen to the loading plates. Please refer to the standard for tension and compression loading setup variations.
- Install the specimen/loading plates assembly into the test machine.
- Mount the displacement gauge on the specimen side or back.
- Apply a tensile or a compressive force to the specimen. Set the speed of testing so as to produce failure within 3 to 6 minutes. The suggested crosshead displacement rate is found in the testing standard.
- Record force versus crosshead displacement and force versus axial displacement, continuously.
- Terminate test at rupture. Record the yield force (if applicable), the maximum force, the failure force, and the displacement at the moment of rupture.
- Record the mode and location of failure for each specimen. The only acceptable failure mode is shear failure of the core material.
- Shear Stress
- Engineering Shear Strain
- 2% Offset Shear Strength
- Ultimate Shear Strength
- Core Shear Modulus
ASTM C273 | Wood and Paper | Shear Testing
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