On the Constitutive Law for the Mechanical Quasi-static Response of Criss-Cross Composites (on the Example of UHMWPE)

In this paper, out-of-plane compression of criss-cross composite materials, i.e. materials with ply stacking sequence of [0∘/90∘]n, is studied experimentally and analytically. All these composite materials have some common properties, such as 90∘ rotation (around the axis perpendicular to the ply planes) symmetry in macroscopic properties;small ply thickness compared to all other linear dimensions (thickness of the whole material, linear dimensions in the ply plane);significantly different Poisson ratios between the fibre direction/perpendicular-to-the-fibre direction and the two perpendiculars to the fibre directions;ply thicknesses between 30 and 70 μ m. A constitutive anisotropic elasto-plastic law for this class of materials is proposed, and its validity with reference to Tensylon™ is verified experimentally. Satisfactory agreement is reached, and the viscous nature of the deviations between the model proposed and the experimental results is revealed. © 2017, Springer Nature Singapore Pte Ltd.