A NUMERICAL APPROACH TO SIMULATE THE BEHAVIOR OF FIBER REINFORCED COMPOSITE MATERIALS

E. CAR; S. OLLER; E. OÑATE

Congreso; European Congress on Computational Methods in Applied Sciences and Engineering. ECCOMAS 2000; 2000

In this work a model to simulate the constitutive behavior of multiphase com-posite materials is presented. This model is based on the classical mixing theory. Due to the presence of complex failure phenomena of composite materials the classical mixing theory is not enough, i.e. debonding phenomena. This phenomena takes place in com-posite materials when there is a relative slip between compoundings and the maximum shear stress of the interface is greater than its yield value. In this case the matrix is not able to transfer the loads to the fiber, so the fiber can not increase its stress state because the matrix-fiber interface can not resist it. The modification in the constitutive model to take into account these phenomena is based on the ideas that the transfer of loads between matrix and fiber change when the matrix plastifies. Due to the presence of anisotropic phases in the composite material a new constitutive model for this compounds in presented. This model is based on an isotropic equivalent formulation which assumes the existence of a fictitious isotropic space where a mapped fictitious problem is solved. Applications examples showing a comparison between a micro model and the constitutive model here presented is given.