ITERATIVE METHOD FOR EXPERIMENTALLY DETERMINING THE MODULUS OF SLIDING OF ANISOTROPIC LONG FIBRE MATERIALS

摘要

The invention relates to an iterative method for experimentally determinating the modulus of sliding of anisotropic long fibre materials, in particular of composite materials reinforced with unidirectional long fibres, by applying a tensile force for determining the corresponding Young modulus, Ex oriented with an angle teta successivelly variable against the fibre axis, where the modulus of sliding G 12 is determined by a known dependance relation between Young modulus Ex and teta i angle, for which Ex has a minimal value on the graph Ex = f(teta) and corresponding to the decoupling of the elongated and shear effects, the successive steps of determining the angle teta i being calculated with a known per se relation of dependance of the angle teta on the modulus of sliding G 12 and on the Young modulus along the longitudinal directions: X=X1 and frontal X=X2 till obtaining a determination error : omega = teta i -1-teta i lower than convenient imposed value.