The use of curvilinear fibre paths to develop variable stiffness laminates is now recognised as a promising technique offering great potential for performance improvements over conventional ‘straight fibre’ laminates. Its manufacture is feasible by fibre placement technologies, such as automated fibre placement. However, these technologies present a set of limitations that need to be included in the design to guarantee the manufacturability and quality of the composite laminates. Although this approach experiences an increasing interest from the specialised literature, most of the works completed overlook the manufacturing reality and, as a result, variable stiffness laminates are not used in industry. This work aims to provide a review of the State-of-the-Art on design for manufacture of variable stiffness in order to highlight the current gaps and research needs. As a conclusion, tools for analysis of the effect of manufacturing defects, manufacturing optimisation of gaps/overlaps or cycle time and the ...

http://journals.sagepub.com/doi/pdf/10.1177/0954405415600012

A review on design for manufacture of variable stiffness composite laminates

European aircraft industry demands for reduced development and operating costs. Tailored Fibre Placement (TFP) is a promising technology which contributes to this aim by reducing structural weight at safe design; it exploits considerable reserves in structures made of Carbon Fibre Reinforcement Plastics (CFRP) by placing the carbon fibre rovings according principal stresses. This paper deals with selected results of 4 research projects in the field of TFP the Institute of Composite Structures and Adaptive Systems of DLR is working in. Within the first already finished project the tool TACO (Tailored Composite Design Code), which is a TFP design tool for lightweight aerospace structures, was developed. Three running follow-up projects deal with basic research investigations, improvement of TACO and its industrial application as well as the automatic determination of the roving distributions.

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Tailored fibre placement optimization tool

As-built fe simulation of advanced fibre placement structures based on manufacturing data

A design algorithm to model fibre paths for manufacturing of structurally optimised composite laminates

3D static analysis of patched composite laminates using a multidomain differential quadrature method

This paper presents two new design tools for lightweight aerospace structures. The first tool is the Tailored Fibre Placement (TFP) design tool TACO. It is used to optimize the fibre orientations of structures made of Carbon Fibre Reinforcement Plastics (CFRP). The optimization concept is explained and results are given for a horizontal tail plane connection beam of an aircraft. The second tool, iBuck, is a fast, semi-analytical local buckling and post-buckling tool for stiffened panels that are loaded in-plane. The panels are assumed to be representative for an aircraft fuselage and are stiffened in axial and circumferential direction. Results are presented for axially loaded panels and compared to FE-results.

/pdf/new-design-tools-for-lightweight-aerospace-structures-4ed0j2yos4.pdf

Philipp Bürmann

Papers

New design tools for lightweight aerospace structures