Pure bending of a continuous fiber array suspended in a thermoplastic polymer in the melt state

Abstract The prediction of the bending moment–curvature and moment-angular rotation relationships for a collimated, fiber-reinforced thermoplastic prepreg in the melt state is the subject of this work. The central assumption of the developed relationship is that the fiber phase controls the deformed state of the composite and the local curvature rate of the fiber phase induces shearing strain rate in the viscous polymer. The corresponding shearing stresses are shown to retard the elastic deformation of the fibers when subjected to curvature-rate. Further, the developed models exhibit the characteristics of the traditional Voigt-Kelvin viscoelastic medium and thereby provide the rich family of corresponding viscoelastic solutions. The results illustrate how the constituent properties for reinforcing fiber and the thermoplastic polymer can be utilized to develop the desired composite constituent relationships necessary for simulation of thermoplastic hybrid forming.