Fracture toughness of a carbon fibre-epoxy composite material

• Main Author: Radford, Donald W.
• Language: English
• Published: 2010
• Online Access: http://hdl.handle.net/2429/23406

Testing has been undertaken to study the applicability of linear elastic fracture mechanics to a carbon fibre-epoxy laminate system. Hercules AS/3501-6 carbon fibre-epoxy prepreg was used to produce laminates which were subsequently cut into specimens of various geometries, sizes, and thicknesses. Plane strain equations were used to calculate values of fracture toughness as the notch proportion, specimen size, geometry, and thickness were varied. The results indicate that the toughness is independent of specimen geometry, size, and thickness; however, the toughness is seen to fall dramatically at increasing values of notch proportion. To substantiate these trends compliance calibrations were carried out for the various specimens. The trends arrived at through the compliance calibration show close agreement with those found using the plane strain method. Together these results indicate that for a narrow range of notch proportions (a/W = 0.2 to 0.5) linear elastic fracture mechanics can be applied, yielding a value of fracture toughness which behaves as a material constant comparable to K[sub 1C]. === Applied Science, Faculty of === Materials Engineering, Department of === Graduate