Tensile properties of real unidirectional Kevlar/epoxy composites

摘要: Abstract Mechanical behaviour, tensile strength and failure modes in real unidirectional Kevlar/epoxy composites, loaded parallel to the fibres, at volume fraction (Vf) range 0.26–0.73, were investigated. It was found that measured strengths deviated from expected values calculated Rule of Mixture. The deviation, which minimal Vf about 0.5, mainly due geometrical deficiencies typical composites. At 0.5 deviation explained by increasing lack matrix between some adjacent fibres squeezing fibres. initial part loading typified straightening out non-axial accompanied fibre/matrix debonding. process completed a stress level 0.6–0.7 composite strength. Matrix damage began this continued develop up final failure. Failure Kevlar noted occur only an extremely short interval coinciding with catastrophic This small scatter fibre