APPLICATION OF THE VIRTUAL FIELDS METHOD FOR THE IDENTIFICATION OF A SHEAR DAMAGE MODEL FOR COMPOSITE MATERIALS

摘要

In the present work the Virtual Fields Method (VFM) has been used to extract the whole set of material parameters governing a nonlinear behaviour law for composite materials. The nonlinearity considered here is mainly due to the damage inherent to the in-plane shear response. The identification method is performed by applying the principle of virtual work knowing the whole strain field onto the surface of a tested specimen. To illustrate the capabilities of the method, the identification is performed on data provided by finite element simulations. Hence, in this paper, numerical aspects related to the method implementation and the identification procedure sensitivity in terms of convergence, accuracy and stability are investigated. A parametric study has been performed to evaluate the influence of the length characterising the identification central area, on the estimated elastic and damage parameters. This work contributed to illustrate that the VFM constitutes a relevant and numerically robust technique for the direct identification of composites nonlinear constitutive law.