Recent study demonstrates cost effective 3D carbon fabric solution in automotive application
Bentley Motors and Sigmatex recently completed a Research and Development program partially funded by the Technology Strategy Board under the acronym ACTS (Advanced Composite Truss Structures). The project included a study of fabrication costs between composites versus the baseline aluminum construction in an automotive structural element. In the study, a sample “A” pillar node was fabricated using the Bentley automated fibre deposition process, finished by pressing, and by the Sigmatex One Piece 3D weaving process with subsequent resin infusion. In this study, the technically superior composite solution was produced using the 3D woven preform and the resin infusion process. In reaching this conclusion, the study put a value of weight saving at €5/kg for this automotive application.
The study demonstrates that 3D woven preforms can be cost competitive in low volume, complex shape automotive applications. Due to the higher mechanical properties and reduced variability through automated process control, the component fabricated from 3D fabric would have a lower weight than the automated fibre placement component and a very significant improvement compared to the aluminum part.
The 3D weaving process that Sigmatex has developed differs from conventional 3D in that the throughput rates are substantially higher resulting in lower costs. This lower cost basis enabled the 3D/infusion approach to compete traditional fabrication processes such as automated fiber placement and hand layup. In production, this type of preform can be nested to reduce scrap and supplied on 100 meter rolls, with approximately 200 preforms per roll.
“The Sigmatex 3D weaving process enables complex components to be manufactured with fibres and weave architectures designed to form integral strength and stiffness. Although a little way off manufacturing a One Piece Woven Body in White, we can demonstrate that 3D woven structures can meet the technical and cost requirements for the Automotive sector.” said Chris McHugh, Technical Manager for Sigmatex.
Lee Bateup, Advanced Vehicle Technologies Specialist for Bentley commented “the programme successfully demonstrated that a 3D woven composite preform was very well suited to the very complex and highly loaded nodal structure within an automotive spaceframe. Sigmatex has made a step change in quality and cost through improved automation compared to a conventional 2D composite. The solution offers very significant weight, functionality and performance benefits compared to the incumbent aluminum component. Combined with reduced investment costs, this is a very attractive proposition for future vehicle platforms.”