The document describes several test geometries used to determine the failure strengths of composite materials, including the Double Cantilever Beam test for mode I failure, the End Notch Flexure test for mode II failure, and the Mixed-mode Interlaminar Fracture test for mixed mode I/II failure. It also lists the Single Cantilever Beam test for skin debonding energy in composite sandwiches, the Centre Notch Flexure test for thin skin debonding, and the Interlaminar Shear Strength test, a three point bend test to determine shear strength.

1. P Double Cantilever Beam (DCB) test geometry Used to determine mode I failure strength of composite materials δ End block h Pre-crack 2h B a P Beam Theory Method: (J/m2)

2. End Notch Flexure (ENF) test geometry Used to determine mode II failure strength of composite materials a P B Pre-crack 2h L L Beam Theory Method: (J/m2)

3. Mixed-mode (I/II) Interlaminar Fracture test geometry Used to determine mixed mode interlaminar failure strength of composite materials B L a P δ Pre-crack 2h Mixed-mode fracture Energy: (J/m2)

4. Single Cantilever Beam (SCB) test geometry Used to determine skin debonding energy for thick skinned composite sandwich structures B Clamp P Core material Pre-crack Clamp a Mixed-mode fracture Energy: (J/m2)

5. Centre Notch Flexure (CNF) test geometry Used to determine skin debonding energy for thin skinned composite sandwich structures B P P Hole δ Pre-crack a Mixed-mode fracture Energy: (J/m2)

6. Interlaminar Shear Strength (ILSS) test geometry Standardised three point bend test used to determine interlaminate shear strength for composite structures P B 10mm δ 2mm 20mm Interlaminate Shear Strength: (J/m2)