Solution for tile inelastic buckling of long fiber reinforced composite materials

This work presents a damage buckling constitutive model of loss of the stiffness in reinforced matrix composite material produced by micro-buckling of the uniaxial long reinforced fibers. This model is a generalization of Kachanov isotropic damage model. The resulting formulation is considered inside the context of the anisotropic composite material and it is integrated in a finite elements code previously developed by the authors for thermo mechanical coupled problems. The resulting code allows the numerical behavior simulation of the fibers instability in long fibers reinforced composite materials. It also takes into account the local instability inside a global instability represented by means a large strain formulation. This formulation is based on the mixing theory of basic substances, general anisotropy, large strains and non-lineal behavior of each basic substance belonging to the composite materials. Due to the wide theoretical field involved in the present work, an effort is made to present the local instability of large fiber reinforced composites and its global influence on the structures.