In-Situ Monitoring of the Fibre Strain Distribution in Carbon Fibre Thermoplastic Composites; Part 1 - Application of a Tensile Stress Field.

The distribution of residual thermal strains and the mechanical response of carbon fibre thermoplastic composites, upon the application of an external tensile stress, have been studied. Confocal laser Raman microscopy has been employed to monitor the Raman wavenumbers of the embedded carbon fibres, within a predefined 'window' of observation. The application of a tensile stress field on the P75/PEEK composite, induces an internal fibre stress/strain gradient due to progressive fibre fracture and matrix microcracking. The spread of the fibre strain distribution is primarily dependent upon the magnitude of the residual thermal stresses and the level of applied stress. In cases where optical monitoring of discontinuities, such as fibre and matrix breaks, is not possible, a statistical approach is pursued for monitoring the micromechanics of failure in these composites.

FILIOU C.;  GALIOTIS Costas; 

1998-11-09

JRC17107

https://publications.jrc.ec.europa.eu/repository/handle/JRC17107,