From TRL2 to Take-off – The A350 Door Sourround Structure

The successful integration of the AFP process into series production was only the beginning of a larger success story. The methodologies developed at Fraunhofer IGCV (formaly known as Fraunhofer ICT-FIL) have proven to be a catalyst for innovation across the aerospace industry and beyond. The expertise gained from door-surround structures is now driving the next generation of aircraft.

• A350 Family Growth: Extending developments to the A350 Freighter and the high-capacity 10-seat abreast version of the A350.
• Next-Gen Materials: Pioneering the transition to thermoplastic composites for large-scale components, including integral frames and pressure bulkheads.

The AFP technology is not limited to aviation but allows for a seamless transfer to diverse high-performance sectors:

• Vertical Lift & UAM: Adaptation for helicopter components such as side shells, flex beams, and tailbooms, as well as emerging Urban Air Mobility (UAM) platforms.
• Space Exploration: Implementing precision placement for extreme environments, including satellite structures and liquid hydrogen (LH2) storage tanks for the Ariane 6 upper stage.

These milestones underscore the core mission of Fraunhofer IGCV: serving as a bridge between high-level research and industrial application. By helping industry partners acquire and implement high-end technologies, we ensure that complex composite solutions become a reliable, everyday reality in production halls worldwide.

At Fraunhofer IGCV in Augsburg, we are pushing the boundaries of composite manufacturing. Our systematic approach to developing Door-Surround Structures demonstrates the complete technology ramp-up—from initial material screenings to the industrialization of full-scale aerospace components.

1. Basic Studies:  Technical Foundation

The journey began with a comprehensive evaluation of manufacturing routes to identify the most efficient method for complex airframe reinforcements.

Technology Screening: Comparative analysis of various manufacturing technologies for high-performance door-surround structures.

Infrastructure Integration: Successful implementation and commissioning of Coriolis Composites AFP machinery at Fraunhofer IGCV (formerly known as Fraunhofer ICT-FIL) facility in Augsburg. Material Validation: Initial feasibility studies utilizing both thermoset prepreg and dry fiber placement (DFP) technologies.

Process Optimization: Systematic parameter studies on 2D laminates to determine optimal compaction, temperature, and speed.

Coupon Testing: Manufacturing of standardized 2D specimens to characterize mechanical properties and material quality.

2. Transfer to Complex 3D Shapes

Moving from flat laminates to 3D geometries requires sophisticated software strategies and a deep understanding of fiber steering.

AFP Programming: Development of specialized CAD/CAM strategies to manage steering radii and minimize layup defects.

Proof of Concept: Validation of the digital process chain through the production of TRL3 demonstrator parts.

Design-to-Fiber-Placement: Establishing design principles by comparing "as-programmed" digital twins with "as-built" layup quality.

Strategic Decision: Final selection of AFP as the core technology for next-generation door frames and definition of initial staggering proposals.

3. From Lab Scale to Full Size

Scaling the process involves managing increased geometric complexity and the physical dimensions of primary aircraft structures.

Industrialization Concepts: Development of manufacturing workflows designed for high-volume factory environments.

Scaling Complexity: Transitioning from simple geometries to full-size, final-design equivalent doorframes with high-complexity plybooks.
Reproducibility Analysis: Conducting rigorous testing across multiple full-scale configurations to ensure consistent manufacturing output.

4. Developing a Serial Process

The final phase focuses on economic viability, process stability, and the stringent certification requirements of the aviation industry.

Process Chain Optimization: Refining the workflow for maximum compatibility with aerospace series production.

Cycle Time Reduction: Optimizing layup speeds and auxiliary tasks to meet industrial takt times.

Stability & Reliability: Increasing process robustness to ensure "right-first-time" manufacturing.

Aerospace Compliance: Meeting the precise tolerances and quality standards required for flight-critical parts.

Technology Expansion: Leveraging the insights gained to push AFP technology into new structural applications.