Apparent interlaminar shear strength

The apparent interlaminar shear strength τM (ILSS) can be determined for fibre-reinforced plastics with thermoplastic or thermoset matrix, provided that a failure of the material can be caused by interlaminar shear during the test.

For this purpose, a test specimen is tested in a three-point bending arrangement, whereby an interlaminar failure is to be achieved by increasing the shear stresses in the test specimen through a suitable choice of the ratio of test specimen thickness to support width. After the failure of the specimen, the fracture surface is evaluated and the failure mode (shear failure, mixed failure of tension, shear and compression, non-shear failure or shearing) is determined.

Sample preparation

  • Sawing
  • Milling

Test conditions

  • Three-point bending arrangement
  • Temperature range from -50 °C to 250 °C
  • Standard climate (23 °C, 50 % humidity)

Standards

Akkreditierte Normen:

  • DIN EN ISO 14130: Faserverstärkte Kunststoffe –Bestimmung der scheinbaren interlaminaren Scherfestigkeit nach dem Dreipunktverfahren mit kurzem Balken

weitere Normen:

  • DIN EN 2377: Luft- und Raumfahrt – Glasfaserverstärkte Kunststoffe – Prüfverfahren zur Bestimmung der scheinbaren interlaminaren Scherfestigkeit
  • DIN EN 2563: Luft- und Raumfahrt – Kohlenstofffaserverstärkte Kunststoffe – Unidirektionale Laminate – Bestimmung der scheinbaren interlaminaren Scherfestigkeit

Results

  • Apparent interlaminar shear strength τM
  • Shear failure
  • Failure modes:
    • Shear failure
    • Mixed failure from tension, shear and compression
    • Non-shear failure

Contact us!