Delamination Model for Laminated Composite Structures using ZigZag Theory

A. EIJO; E. OÑATE; S. OLLER

Conferencia; Computational Plasticity XI - Fundamental and Applications - COMPLAS- XI; 2011

In this work is presented the recent developments of a new potential alternative to simulate the phenomenon of delamination in beams, plates and shells of laminated composite materials.On the one hand this technique uses the new one- [1] and two-dimensional finite element to predict the kinematics of the laminated composite for beams and plates/shells, respectively. They were formulated from the refined zigzag theory proposed by Tessler et al. [2, 3]. In [1] was amply shown that the typical kinematic of composite is very accurately captured with this simple approximation.On the other hand material degradation is simulated with a damage formulation. So, the procedure proposed here to take into account the reduction of the material stiffness property uses the Simo-Ju [4] isotropic damage model.The key advantage of this method is that it not requires a three-dimensional structure discretization, which makes particularly well suited to simulate large scale models of composite structures, such the aerospace field, in which the computational cost of using 3D elements may make the simulation computationally unaffordable. Also it is important to remark that this technique not needs to predefine the region where it is supposed to take place the delamination. Another significant advantage is that the used finite elements have one and two more degrees of freedom per node than the first order shear deformation theory (FSDT) for beam and plate, respectively.The recent numerical results show the skill of this promising alternative to capture the phenomenon of relative displacement between plies in type II fracture modes. To enhance the accuracy of the numerical simulation of delamination in order to obtain better predictions it is necessary to develop a new isotropic damage model which takes into account the difference between volumetric and deviatoric degradation.