Efficient screening of composite structures using the extended 2D FEM approach in Meta together with a state of the art failure initiation criterion

In order to assess complex composite structures, the full 3D stress tensor is needed to ensure that all possible failure modes can be captured. Conventional shell elements only give accurate results for the in-plane stress components, while the out-of-plane components are neglected. The implementation of the Extended 2D FEM approach [1] into Metapost [2] makes it possible to get the full 3D stress tensor from second order shell elements. With the full stress tensor, state of the art set of failure initiation criteria can be used to evaluate the component. Two different cases are used to show the applicability of the procedure. The first example is a simply supported plate from the literature [3] is in particular used to demonstrate the visualisation capabilities in Metapost. The second example is a set-up used to measure\ua0 the out-of-plane strength of composite materials [4], it is here analysed using both the Extended 2D FEM approach and a state of the art set of failure initiation criteria, LaRC05 [5]