EFFECT OF LONGITUDINAL SPLITTING ON TENSILE-STRENGTH OF UNIDIRECTIONAL ARAMID FIBER REINFORCED-PLASTICS

An increase in aramid SVM (trademark of polyparaamidobenzimidazole fiber) content up to 85 vol. % leads to an increased tensile strength of the composite. An increase in fiber content, V(f), leads to a change of the fracture mode from fiber control at low V(f) to matrix and matrix/interface dominated longitudinal splitting of the composite at high V(f). The correlation between transverse properties and longitudinal tensile strength of different aramid fiber reinforced plastics was investigated. Longitudinal splitting of the composite leads to a decrease in longitudinal tensile strength. Shear strength of the aramid fiber reinforced plastic possesses a low sensitivity to its resistance to longitudinal splitting. For this the transverse strength or interlaminar fracture toughness of the composite may be used. Matrix plasticization leads to an increase of aramid Terlon (trademark of polyparaphenelenterephthalamid) fiber reinforced plastic tensile strength due to suppression of longitudinal splitting.