Failure mode of thermohydroscopically aged composites: case of NC2 © carbon fibre laminates

T.T.Q Nguyen (1) , J M Molimard (1, 2) , A M Vautrin (1) , J M Béraud (3)

1 LGF-ENSMSE - Laboratoire Georges Friedel
2 CIS-ENSMSE - Centre Ingénierie et Santé
3 HEXCEL Reinforcements, F-38630 Zi Les Nappes, Les Avenieres, France

Stitched multiaxial laminates NCF can be a new high performance preform for manufacturing complex structures by RTM or infusion processes (LRI). Nevertheless, the stitching leads to a particular morphology with resin-rich regions inside the material, as illustrated Figure 1. The latter become critical areas and a specific crack network will develop in the bulk of the laminates when they are subjected to the hygrothermal ageing cycles. To a better control of the cracking behaviour within the resin-rich regions under certain aeronautical application in service, a thermal/hygrothermal-mechanical coupling at different ageing states has been investigated by the full-field image correlation at mesoscopic level: 1/ material at initial state; material with initiated cracks 2a/ in plane (at 135° ply), 2b/ in thickness (at 90° plies) and finally 3/ material with large cracks developed in all resin-rich regions inside plies. The 0°-tensile test was applied throughout all testing configurations, strain gauges and microscopic observations helped to validate the obtained results. The typical material studied was NC2 © (Non Crimp New Concept) - a specific family of NCF, of sequence QI [135/0/45/90]S and stitching yarn PET 76dtex.

Domaines: Biomécanique [physics.med-ph]

T.T.Q Nguyen, J M Molimard, A M Vautrin, J M Béraud. Failure mode of thermohydroscopically aged composites: case of NC2 © carbon fibre laminates. 16th International Conference on Experimental Mechanics, Jul 2014, Cambridge, United Kingdom. ⟨hal-01406449⟩