Addcomposites & CAELESTIS: Innovative Composites Manufacture for Sustainable Aviation
Perhaps more than anything else, the fuel behind CAELESTIS lies in the untapped potential of composite materials for the aviation industry. By utilising digital twins, we hope to qualify much lighter aircraft making use of these materials ¬ and reduce carbon emissions along the way. These materials are made from two or more constituent materials that, when combined, create a material with characteristics different from the individual components. Composites are already put to use in aviation as they have such a high strength-to-weight ratio, making them already -suited for use in vital components such as wings or and tail structures. In addition to being both stronger and lighter than certain traditional materials such as aluminium or steel, they’re also highly resistant to fatigue, corrosion, and wear – yet total material domination by composites remains to be seen. Enter Finland’s pioneering company, Addcomposites Oy.
“The vision of Addcomposites is to enable every manufacturer to become composites manufacturing ready with the help of advanced technology,” explains CEO Pravin Luthada from the company’s base in Espoo, Finland. “We aim to achieve this with our cutting-edge plug-and-play AFP-XS solution, which transforms any robot into an Automated Fiber Placement (AFP) system, enabling seamless and efficient composite production.” The innovative approach behind the solution offers unparalleled flexibility and adaptability for composite manufacturing has given the company a global presence and the highest number of AFP systems in operation, spread across the aerospace, defense, and space sectors – not to mention groundbreaking research & innovation developments, such as CAELESTIS. Nonetheless, CAELESTIS is Addcomposites’ very first Horizon Europe project.
Presently, Addcomposites comprises a team of 12 engineers, based at their 300m2 facility in Espoo – known internally as the Million Euro wonderlands for Engineers. “We have all the cool toys!” grins Luthada. “…Automated CNC machines, slitting machine, AFP system that can run dry, thermoset, thermoplastic material for curved or wound parts, an automation lab for digital twin application development, and a play area!”
As a member of the CAELESTIS consortium, Addcomposites is providing vital technology and know-how on the path to sustainable aviation, making contributions across the project’s various work packages. Specifically, the company’s world class digital twin software – AddPath™ – forms a key part of the puzzle, streamlining AFP process planning, simulations, real time monitoring, and Design for Manufacturing (DFM). “AddPath™ is the key to realizing the vision for accessibility of automated composites manufacturing,” says Luthada. “In the project workflow, it is one of the very first process steps the process designer has to interact with. AddPath™ simulates all the process motion and material-related defects that can occur. These defects are than embedded onto the imported flow simulation mesh for a simplistic resin flow simulation.” In short, they’re working on identifying manufacturing defects, a key part of the process behind qualifying new parts. Luthada and co have worked on similar projects in defence, space, automotive, and even sports in the past. Aviation however, has the toughest restrictions, with tighter defect acceptance margins making it their biggest challenge yet.
“Manufacturing defects in composites could be attributed to few key sources,” explains Luthada. “Material defects, which in the case of AFP comes from slitting tolerances of the tape, a standard accepted tolerance is this regard is +/-0.127mm, meaning is we were to place such tape with an absolutely accurate robot the maximum gap possible would be 0.254 mm.
“Moving onto process-induced defects, the robot or gantries placing the tape are not perfect, and the AFP heads are not perfect, and they add to the additional error usually to the tune of 0.13mm – 0.4 mm absolute linear tolerance.” Luthada also goes on to explain how the process of trying to cover curved surfaces with flat strips of un-stretchable tape can – and does – lead to folds or wrinkles, with a variety of unpredictable possible outcomes, unlike with more conventional metal components. “In simple words manufacturing decides the strength of the final part in composites, whereas with metal its all pre-decided.”
So how will CAELESTIS’s groundbreaking work contribute to eliminating those composite defect doubts from the equation entirely? Luthada thinks the solution will, and can only, be a digital one. “I have learned a lot about composites processes over my 12+ year of working with them, and from my POV the most important thing is the building of the digital thread across the process chain where data can be captured corrected without any breakage, I believe such system would be able to improve the overall production efficiency not only for the ongoing products but provide a much better predictive capability that is grounded in data, will provide simulation that are much closer to reality.”