Analysis and Design for Accelerated Production and Tailoring of composites (ADAPT)

Lead Research Organisation: University of Bath
Department Name: Mechanical Engineering

Abstract

If demand for production of next-generation, short-range commercial aircraft is to be profitably met, current methods for composite airframe manufacture must achieve significant increases in material deposition rates at reduced cost. However, improved rates cannot come at the expense of safety or increased airframe mass.

This project will enable a fourfold increase in productivity by establishing novel manufacturing techniques that speed up deposition of stiffness tailored material. New continuum mechanics-based forming models will ensure delivery of better products by minimising occurrence of manufacturing defects. In a parallel stream of activity, new methodologies for analysis and design of composite structures in which the ply angle and thickness of fibre-reinforcement is spatially tailored, both continuously and discretely, will reduce the need for stiffening, leading to significant savings in structural mass (by up to 30%) and manufacturing cost (by up to 20%). Potential structural integrity and damage tolerance issues, such as transition in fibre angle and tapering of laminate thickness from one discrete angle to another, will be addressed.

The project will engage a multidisciplinary team of engineers and applied mathematicians to develop novel manufacturing and modelling techniques. An embedded university-industry partnership will focus on the creation of new manufacturing and analysis capabilities, supported by fundamental research. Academics at Bath and Exeter will partner with the National Composites Centre and with industrial collaborators that span the airframe supply chain. The project will enable production of high performance composite components at rates suitable for the next generation of short-range aircraft. There are also opportunities for impact in the wider composites manufacturing industry, including automotive and energy sectors.

Planned Impact

Successful resolution of the process and performance issues associated with high-rate production of laminated composites is fundamental to the long-term success of UK composites manufacturing, both in terms of advanced wing design, aero engine development and manufacture of major aerospace components. The latter is predicted to generate opportunities worth $4.5tn for UK suppliers over the next 20 years.

Specific impact (and beneficiaries) will arise in the design and manufacture of laminated composite structures in the form of:

1. New process simulation software (OEMs - Airbus, Boeing & Bombardier; Tier 1 suppliers - GKN and others);
2. Improved design principles (OEMs & Tier 1 suppliers);
3. New high-rate manufacturing techniques (OEMs, Tier 1 suppliers & material suppliers).

Significant opportunities for impact also exist within the wider composites manufacturing industry, e.g. in the automotive and energy sectors.

The proposed work complements national research activity elsewhere; specifically, the EPSRC Centre for Innovative Manufacture in Composites and the National Composites Centre. Full transparency of developments will be maintained with these national centres to avoid overlap and enhance impact.

Publications

10 25 50
 
Description We have devised a new method for determining the formability of a stack of layers of different fibre orientations.
Exploitation Route To improve manufacturability of composite laminates
Sectors Aerospace, Defence and Marine

 
Description Subsequent research by Johnson PhD (2015-1019) and Scarth (PDRA on the ADAPT EPSRC project (Butler, Rhead & Dodwell (Exeter, 2016-2020)) created a new algorithm for design of laminates with good formability without defects. This methodology was validated by forming trials carried out using an industrial-scale former at the GKN Composites Research Centre on the Isle of Wight. The new compatibility index helped to underpin the problematic stacking zone in A350 flaps at GKN Fokker. This has been resolved in a hand-layup trial, and has guided fibre steering definition for stacking around regions of double curvature leading to produce process improvements in spar and flap laying (ATL and AFP) machines.
First Year Of Impact 2018
Sector Aerospace, Defence and Marine
Impact Types Economic

 
Title Formability algorithm for UD composite prepregs 
Description In order to meet demands for increased production rates of laminated composite components, aerospace manufacturing is being forced towards highly automated production processes such as forming. However, such automated processes increase the likelihood of inducing defects that lead to manufacturing cost and time inefficiencies which must be avoided. This paper introduces a new compatibility index, based on comparison of minimum energy (resin dominated) modes of adjacent plies that identifies stacking sequences which minimise defect formation. The index is validated using an experimental process where seven laminates with different stacking sequences are formed onto a complex tool geometry using an industrial double diaphragm former. Experimental results confirm that sequences with a high compatibility index produce defect-free parts at elevated temperature. Specifically, sequences with 90° interface angles (high compatibility indices) promote the most formable solutions and continuous 45° interfaces that spiral (e.g. 45/0/-45/90) which have a low compatibility index, produce the most problematic forming conditions owing to a shear locking behaviour. Laminate stacking sequence is thus shown to be a significant contributor, alongside temperature and vacuum rate, to quality of formed parts. The compatibility index method can therefore be used to increase production rate and quality in laminated composite manufacturing, leading to significant cost and efficiency savings. 
Type Of Material Improvements to research infrastructure 
Year Produced 2019 
Provided To Others? Yes  
Impact Algorithm has been used by GKN to evaluate formability of aerospace parts. It is also being applied to a manufacturing demonstrator at the National Composites Centre.