CWA 17896:2022

This document provides a test method for the determination of the adhesive properties in joints of continuous fibre reinforced polymer matrix composite structures using the Lap Strap specimen.
The evaluation includes the optional concurrent use of the non-destructive technique of the Electrical Resistance Change Method (ERCM) and/or Acoustic Emission (AE) for the monitoring of the debonding of the lap from the strap optionally. The ERCM NDE technique has a limited application only on carbon fibre composites due to the inherent electrical conductivity of the carbon fibres.
This test applies to composites manufactured with continuous carbon fibres (woven or unidirectional) and thermoset or thermoplastic matrices, with quasi-isotropic lamination. This methodology can be used on repairable or self-healing composites in order to estimate the repair or healing efficiency respectively.
Safety aspects about manufacturing and mechanical testing of the composites are excluded.