STRESS-DISTRIBUTION IN AND AROUND A SPHERICALLY ENDED FIBER EMBEDDED IN A POLYMER MATRIX

The effect of fiber end geometry, especially one with an enlarged sphe rical end, on the stress distribution in a polycarbonate/short glass-f iber reinforced model composite was studied using photoelasticity and finite element analysis (FEA). The role played by the fiber/matrix int erfacial strength was also investigated. The photoelastic method was a pplied to examine the stress distribution in the vicinity of a single fiber embedded in a thermoplastic polycarbonate matrix. Linear elastic , axisymmetric FEA was carried out to investigate the fibers effective ness as a load bearing constituent, the effect of interfacial debondin g, and stress concentration near the fiber ends. Both photoelastic ana lysis and FEA demonstrated the efficiency of the spherical enlarged fi ber end in load transfer ability and in delayed debonding, which may b e important in enhancing strength and modulus of thermoplastic matrice s.