Inluence of water up-take on interlaminar fracture properties of carbon fibre-reinforced polymer composites

摘要: Composite materials in practical use can be subjected to a wide variety of different loading conditions. The most important conditions are mechanical stresses and environmental attacks. An issue major concern the utilization composites is associated with occurrence delaminations or interlaminar cracks, which may related manufacturing defects induced service by low-velocity impacts. main attacks temperature, humidity, radiation, chemical exposure. Three were investigated; two thermosetting matrices (unmodified toughness-modified epoxy, EP EPmod) one thermoplastic matrix (semicrystalline polyetheretherketone, PEEK), all reinforced unidirectional continuous carbon fibres. Samples these exposed water baths temperatures; they taken for testing after various time periods. As result absorbed moisture, GIC-values increased moisture content samples, whereas GIIC-values decreased. By means scanning electron microscopy, fracture surfaces examined. Evidence was found that increase due greater ductility (as absorbed) hence more energy-consumptive fibre-bridging. On other hand, interface failure, as well loss shear strength epoxy increasing amount absorbed, responsible decrease GIIC-values. system (CF/PEEK) exhibited no influence on Mode I property, but values II.