On the Displacement Field for Unidirectional Off-Axis Composites in 3-point Flexure - Part II: Numerical and Experimental Results

Abstract

The displacement field calculated in Part I of this work is numerically analysed for specimens of IM7-8552 epoxy matrix based carbon fiber reinforced unidirectional composite material. Three-point tests have been performed in 5 specimens with different fiber orientation, using 10 spans for each specimen. Theoretical displacement fields obtained in Part 1 have been used for showing level curves on supports and load cylinder lines, in order to analyse the suitability of assumptions concerning boundary conditions and load application. Middle point load-displacement curve slopes obtained from displacement field equations and from Classical Laminated Beams Theory are compared with experimentally obtained results. On the other hand, in-plane shear modulus has been calculated in different ways, knowing the other elastic constants of the material and the experimental load-displacement curve slope. The agreement between numerical and experimental results is rather good in all cases.