About the event
Damage Modelling in Composite Laminates
The modelling of damage and failure on composites is still an unresolved problem in many aspects. Amongst others:
1). - The existing numerical techniques or methods often diverge before the virtual failure of the material.
2). - There are different concepts about how to model failure. This could be based on failure criteria.
In general, these criteria are nonlinear functions of the stress components. They have been extensively used in the past decades. Their main shortcomings range from abortion of the numerical process to poor replication of switching –if any at all– between distinct damage modes in a time–marching numerical method. There is the most recent option of using progressive damage models (PDM) that overcomes some of the problems of failure criteria but PDM cannot replicate discontinuities on its own.
3). - Different strategies for modelling the discontinuities exerted by the cracks: meshless methods, cohesive elements within Finite Element Method (FEM), FEM with remeshing, XFEM, DGFEM… A recently developed PDM for composites (CPDM)  that allows the switching between different damage modes during the numerical process, ranging from matrix cracking/crushing (Fig.1) to fibre breakage or delamination will be presented.
CPDM  performs the simulation of distinct types of damage in laminated composites. It involves the characterisation of the damage directions in which several modes of damage propagate taking into consideration strain-rate dependence. A mapping between the strain and stress spaces for the computation of the damage surfaces as well as damage initiation criteria in the space of strains are used whereby numerical stability is optimised. The capabilities of the technique are shown by means of low velocity impact tests on composite laminate. In addition, relatively novel techniques such as the eXtended Finite Element Method (XFEM)  applied to the simulation of crack propagation in composite structures will also be shown.
.- J.L. Curiel-Sosa, S. Phaneendra, J.J. Muñoz, (2013). Modelling of mixed damage on fibre reinforced composite laminates subjected to low velocity impact. International Journal of Damage Mechanics, 22(3):356-374.
.- J.L. Curiel-Sosa, N. Karapurath, (2012). Delamination modelling of GLARE using the Extended Finite Element Method. Composite Science Technology, 72 (7): 788-791.
.- J.L. Curiel Sosa, N. Petrinic, J. Weigand, (2008). A three-dimensional progressive damage model for fibre-composite materials. Mechanics Research Communications, 35 (4): 219-221.