Sandwich Panel Flatwise Shear Test Fixture (ASTM C273)

Model No. WTF-TS (Stainless Steel)

IMG_2836

Fig. 1: Test fixture with three pairs of loading plates.

Either a sandwich panel or the core material itself can be tested, in shear parallel to the flatwise plane.

A unique feature of the Wyoming Test Fixtures, Inc. design, shown in Fig. 1 above, is that the same fixture can be used to apply either a tensile or a compressive loading, although a tensile loading is most commonly utilized.  (This eliminates buckling as a potential failure mode.)

Most fixtures are capable of applying only one loading mode or the other.  Even ASTM Standard C273 (Reference 1), while permitting either loading mode, suggests two separate fixtures.

Wyoming Test Fixtures, Inc. can supply a fixture capable of applying a compressive loading specifically in the manner indicated in ASTM C273.  This fixture is identified as Model WTF-CS, and is described in Section A-8 of this catalog.  However, this fixture is rarely used.

The fixture shown in Fig. 1 is designed to accommodate a 0.75 in. thick specimen as large as 9 in. long and 3 in. wide. An arbitrarily narrower, shorter, and thinner or thicker (e.g., 0.5 in. to 1 in. thick) specimen can be tested, however, in this same fixture. Any other non-standard fixture size can also be provided. The top and bottom connector pieces have a 1"-14 threaded hole to be used to attatch to the testing machine. Custom adapters can be made to attatch to any type of connection for a specific testing machine, but are not included with the fixture.

The Wyoming fixture is uniquely designed so that both surfaces of each loading plate can be used, thus doubling the life of the plates. Three pairs of loading plates are provided with the fixture.  Additional plates can be supplied, at nominal cost.

Special modifications can also be designed.  The photo below shows an example.  Bonding plates of a special configuration have been supplied, with pipe fittings added to permit pressurization of the core while shear testing.

sandwichpanel flatwise shear test fixture_1

Fig. 2:  Sandwich Panel Flatwise Shear Test Fixture with special bonding plates containing fittings for internal pressurization of the core during testing, and optional adapters.

Source of Additional Information:

1)    ASTM Standard C273-11 (2011), "Shear Properties in Flatwise Plane of Flat Sandwich Constructions or Sandwich Cores," American Society for Testing and Materials, West Conshohocken, PA (first issued in 1951).