Multiscale Modelling of Lamination Defects in Curved Structures

Finite element (FE) analysis of curved aerospace laminates has the potential to offset the cost of the expensive experimental testing that is required for certification. However, the number of degrees of freedom necessary to model entire parts (e.g. a wing spar) or to sufficiently resolve defects in smaller parts is extremely high. In order to solve these large problems efficiently a high level of parallelism is needed. For this reason a preconditioner suitable for large anisotropic problems has been implemented in the High Performance Computing library DUNE (Distributed and Unified Numerics Environment). GenEO coupled with an iterative solver such as CG can solve large problems quickly on hundreds of computer cores. This preconditioner can then be used to test the effect of varying the slope of a simple wrinkling defect on the initiation of damage. A convergence analysis of this example problem shows that models with fewer than 4 elements through-thickness in each ply and interface layer do not yield a good approximation of the stresses.