Casy Study – University of Sheffield/ AMRC
Challenge
The goal of this project was to identify, assess, and refine innovative, flexible manufacturing techniques for high-value aerospace components, enabling determinate assembly with greater precision and efficiency.
Background
The University of Sheffield’s Advanced Manufacturing Research Centre (AMRC) collaborated with BAE Systems, the lead partner, and a consortium including Toolroom Technology Limited (TTL), the University of Nottingham (UoN), and Spirit Aerosystems. Their joint effort focused on developing and validating measurement-assisted determinate assembly (MADA) techniques.
MADA integrates metrology, design, and manufacturing to ensure precise large-scale assembly. The AMRC team tested these methods using a representative aircraft structure. Engineers from the machining, composites, and integrated manufacturing groups contributed to the project, which was grant-funded by Innovate UK.
The research focused on three primary areas:
- Adaptive and accurate machining led by the AMRC’s machining and composites teams in collaboration with TTL.
- Robotic assembly and automated inspection conducted by the University of Nottingham.
- Digital twinning using Unified Namespace (UNS), explored by the AMRC’s integrated manufacturing team.
The objective was to enable flexible part machining independently of their counterparts, facilitating seamless assembly at the University of Nottingham’s Omnifactory facility.
Innovation
The AMRC’s machining team, in collaboration with TTL and UoN, developed an adaptive machining process flow. This process was successfully applied to 11 parts of the BAE Systems representative aircraft structure.
Key steps included:
- On-machine measurement to determine the true part position.
- Datum setting and compensation to align parts accurately.
- Nominal hole drilling, including installation and use of an automatic right-angled head (RAH).
- Coordinate measuring machine (CMM) inspection to verify hole positions.
- Adaptive hole drilling followed by final CMM inspection.
The AMRC’s composites team, working with BAE Systems and tool suppliers, developed dry drilling strategies for machining carbon-fiber-reinforced polymer (CFRP)/Hysol/aluminium stacks. A design of experiments (DoE) approach helped determine optimal cutting parameters for various tool types. Statistical assessments of tool capability guided the selection of the most promising strategies for further development.
The integrated manufacturing team explored Unified Namespace (UNS) as a means to establish a digital thread—connecting integrated data sources across product lifecycles. This work extended AMRC’s Factory+ framework, an open-source reference model for connected manufacturing. The UNS approach ensures interoperability and traceability by structuring data access and standardising information exchange.
In modern digital architectures, integrating a digital thread with UNS supports seamless data capture, real-time notifications, and efficient handling of high-frequency data streams. This framework also enables effective transfer of large metrology reports, both from machine tools and dedicated measurement systems, to enhance manufacturing insights.
Results
AMRC’s machining experts successfully applied nominal and adaptive drilling to all BAE Systems aircraft structure parts. This process achieved unprecedented accuracy, enabling fully automated robotic assembly at the University of Nottingham without manual adjustments.
The composites team made significant progress in dry machining of CFRP/Hysol/aluminium stacks, gaining valuable insights into chip load and tool temperature effects.
The integrated manufacturing team expanded the modular architectural specification for UNS, ensuring optimal data articulation. A single machine tool can generate up to 5GB of data daily from just 14 data metrics at 500 Hz. Efficient data management ensures that only necessary information is transferred, optimising business benefits and reducing unnecessary storage costs.
Impact
The Flexcelle project has set a new benchmark for manufacturing and assembly in future aircraft programs, particularly in assembling flexible, high-value aero-structural components. It has also helped establish new European standards for determinate assembly and metrology-assisted determinate assembly.
By refining workflow understanding, an effective information management system can be established across a product’s lifecycle. This provides both real-time insights and historical analyses, supporting ongoing process optimisation and contributing to the concept of a product’s digital passport.
The stack machining research conducted in this project has played a key role in defining BAE Systems’ future robotic stack drilling strategies, shaping machining parameters and philosophies for upcoming aerospace programmes.
