Experimental investigations regarding the anisotropic properties of pre-impregnated woven carbon fibre-reinforced epoxy resin

Abstract In this work, the variation of the stiffness and strength with the weave pattern orientation of a twill carbon fibre weave pre-impregnated system was investigated. Singe-ply sheets were manufactured using vacuum-assisted curing at a temperature of 120 °C for 8 hours. Specimens were cut at 0°, 15°, 30°, 45°, 60°, 75° and 90° respectively, and subjected to tensile tests at room temperature, using a 5mm/min crosshead travel speed. The results show a symmetric variation along the 45° angle, the obtained stiffness values being between 8.53 GPa (at 45°) and around 59 GPa (at 0° and 90°), while the strength varied between 76 MPa (at 45°) and around 700 MPa (at 0° and 90°). In addition, it was observed that specimens oriented at 0° and 90° exhibited a brittle behaviour while the rest where characterized by ductile failure with significant plastic deformations.