IITRI Compression Test Fixture GZ IT-50

The IITRI compression test fixture is used for the determination of characteristic material properties under compression load.

With this test fixture short, long or continuous fibre-reinforced thermosets or thermoplastics can be testet as well as unidirectional layers or fabrics, multi-layer structures and sandwich laminates. Even isotropic material, e.g. resin or glue, can be tested by use of this test fixture.

The test fixture is required for testing fibre-reinforced plastics to prevent the specimen from buckling. Compared to the Celanese compression test fixture GZ C-20, the IITRI test fixture has the advantage that both testing according to ASTM D3410 and DIN EN ISO 14126 or similar is possible. This means that specimens with a length of 110…160 mm and a width of 6…25 mm can be tested. According to the standards, the use of tabs is not absolutely necessary, but is recommended in order to avoid a too large stress jump between the clamping area and the free test surface and consequently clamping breaks. Strain gauges are applied on both sides in the middle of the specimen in order to determine compressive stiffness, elongation at break and buckling. The testing device consists of clamping wedges, which deflect the axial load of the testing machine into a transverse load for clamping the specimens according to the self-reinforcing principle.

Features & Benefits

  • Stable compression test fixture for static loads up to 50 kN
  • The design allows a specimen change within the device, i.e. the clamping wedges do not have to be removed for specimen change
  • Changeable clamping wedges for different materials and fiber orientations
  • Very stiff and durable design for easy operation to achieve smallest standard deviations
  • Stainless steel design of all components for use in climate chambers (-60…+150 °C)


  • Clampings cross-, lenghtwise-, transverse- milled or diamond coated
  • Adapter for connection to all common electromechanical and servo-hydraulic universal testing machines
  • Compression plates with adapter for all common electromechanical and servo-hydraulic testing machines


  • ASTM D3410, Standard Test Method for Compressive Properties of Polymer Matrix Composite Materials with Unsupported Gage Section by Shear Loading“, ASTM, 2016
  • DIN EN ISO 14126, “Fibre-reinforced plastic composites – Determination of compressive properties in the in-plane direction“, DIN, 2000
  • DIN 65375, “Aerospace; fiber reinforced plastics; testing of unidirectional laminates; compression test transverse to fiber direction“, DIN, 1989
  • DIN EN 2850, “Aerospace series – Carbon fibre thermosetting resin unidirectional laminates – Compression test parallel to fibre direction”, ASD-STAN, 1991

Further Information