Computational structural tailoring of continuous fibre reinforced polymer matrix composites by hybridisation of principal stress and thickness optimisation

Anisotropic composite material properties require special designing capabilities to fully exploit the remarkable properties in longitudinal fibre direction for stiffness and strength improvement. Therefore an optimisation scheme with hierarchical structuring of an optimality criterion based orientation optimisation and a gradient based technique for thickness optimisation is presented. The procedure is applied on two different space scales. Orientation optimisation based on principal stress directions is applied on a local laminate position. There fibre directions are affixed throughout the laminate until convergence is reached. On a local ply position thicknesses are determined in an iterative procedure. It is switched between both algorithms until global convergence is achieved. The application of algorithms on two different space scales leads to a robust engineering approach. The ability of the presented algorithm is tested with a numerical example and a structural optimisation of laminated composites is shown.