Toughness of the fiber/matrix interface in nylon-6/glass fiber composites

The aim of the present study is to investigate the effects of the temperature and fiber surface finishing on the interfacial fracture toughness of nylon-6/E-glass fibers composites. The fracture toughness evaluation is based on a new method, recently proposed by the authors, which yields the strain energy release rate associated with the fiber/matrix interfacial debonding, Garrest, as a combination of a finite element analysis and experimental measurements on embedded single fiber microcomposites. For the unsized E-glass fibers an interface toughness of 165 Jm-2 has been found, while for the polyamide and epoxy compatible sized E-glass fibers higher interfacial debonding energy values of about 340 Jm-2 have been measured. Both sized and unsized E-glass fiber microcomposites showed a strong decrease of the interfacial toughness as the temperature increased. © 1998 Elsevier Science Limited. All rights reserved.