Analysis Of Nonlinearities In Mechanical Behavior Of Textile Composites
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A numerical approach was proposed for simulation of nonlinear behavior of some textile composite configurations; in these materials, the fiber waviness can be significantly reduced under loading, introducing important modifications of mechanical behavior, mainly concerning the in plane stiffness. This study has been developed for two plane weave textiles for aerospace and general applications: a triaxial carbon fiber/ester-cyanate resin and a biaxial glass fiber/PP single layer, which have been characterized on the basis of experimental or bibliography data, focusing on the description of the global elasticity modulus and its variation with the strain level. Experimental data show the crucial importance of nonlinear effects without the possibility, at the moment, of separating material from geometry non-linearity. A numerical analysis based on the use of Finite Element method has been developed, modeling the textile structure at a semi-microscopic level. Basic laminar theory has been used to calculate the elastic properties of a single yam, while the yam geometry has been accurately described. Numerical results demonstrated that the ability of the model to describe the real textile behavior is dependent on the geometrical yam complexity and the contribution of material non-linearity.