DETERMINATION OF LONGITUDINAL AND TRANSVERSE-SHEAR BEHAVIOR OF CONTINUOUS FIBER-REINFORCED COMPOSITES FROM VEE-BENDING

Single-curvature bending of fibre-reinforced thermoplastic (FRTP) comp osites has been demonstrated to be a useful method for determining the longitudinal shear behaviour of these materials. This paper further e xamines the vee-bending method as a means of analysing the transverse shear response of a glass fibre-reinforced polypropylene material. Lam inated strips, with layers possessing reinforcing fibres aligned eithe r parallel or perpendicular to the bend axis, are subjected to a novel bending operation between two highly polished platens, designed in su ch a way as to ensure a constant rate of shear deformation. Interpreta tion of the material's longitudinal and transverse behaviour is made b y way of an idealised fibre-reinforced material (IFRM) model subject t o the kinematic constraints of incompressibility and fibre inextensibi lity. The experiments demonstrate the suitability of the method for co mparing the transverse and longitudinal shear behaviour of such materi als. (C) 1997 Elsevier Science Limited.