Additive Manufacturing and Automated Fibre Placement (AFP) technologies have enabled a new class of fibre-reinforced materials known as Variable Angle Tow (VAT) composites. Unlike traditional laminates, VAT composites allow fibres (typically carbon or glass) to follow curved, spatially varying paths. This capability lets engineers tailor stiffness and strength exactly where needed, achieving lighter, stronger, and more efficient structures.
Yet this potential remains largely untapped. Steering brittle fibres along tight curves introduces gaps, overlaps, and kinks that degrade performance. These defects arise from complex interactions among process parameters, such as temperature, speed, pressure, and curvature, and their effects propagate from the microscopic fibre–matrix scale to the full structure. Since existing design tools cannot capture this multi-scale behaviour, VAT composites remain costly to design, difficult to manufacture, and uncertain in performance.
The PRE-ECO project (A new Paradigm to RE-Engineering printed COmposites) addressed this challenge through a radical rethinking of how such materials are conceived and engineered. Its goal was to build a new framework linking the manufacturing process, material behaviour, and structural performance of tow-steered composites. Specifically, PRE-ECO aimed to:
1. Develop multi-scale models simulating the behaviour of VAT composites from fibre-matrix to component level;
2. Create a hybrid metamodeling platform combining physics-based and machine-learning approaches to quantify and optimise manufacturing defects; and
3. Define new design-for-manufacturing principles, allowing engineers to include AFP and 3D-printing constraints at the design stage.
PRE-ECO achieved these objectives, establishing a cross-disciplinary methodology that unites structural mechanics, computational modelling, materials science, additive manufacturing, and artificial intelligence. It delivered advanced numerical tools, validated models, and experimental data that together form a new paradigm for the digital design of composites. The results pave the way for lighter, more reliable, and sustainable structures in aerospace, transport, and energy applications, contributing to lower fuel consumption and reduced environmental impact.
