Préformage de pièces composites 3D par couture "one-sided" et renforcement par touffetage

Abstract

To reduce the cycle time of composites parts, industry is looking for new assembly methods. The CRIAQ COMP-501 project aims to define an innovative process to preform complex shape part of dry carbon fiber reinforced polymer (CFRP). The selected technology is « One-Sided Stitching® » (OSS®). The target is the production of a stiffened panel « near-netshape » assembly by OSS®. The objectives are to study the influence of stitching on mechanical performance. The geometry is inspired by conventional aircraft structural panel. First, the influence of stitching parameters was studied on flat parts to determine best way to use OSS®. Then experimentation on T-stringers allowed definition of the best position for stitching yarn into the preform. Experiments have showed than the noodle area is the weakness of T-stringers, this study searched for a way to reinforce this spot. To solve the noodle issue, tufting is used. A process to preform by OSS® and reinforce by tufting has been create. Web tear-off tests show encouraging performances on interlaminar strength. If OSS® does not result in improvements of mechanical properties it eases production, manipulation and stability which are necessary keys for dry CFRP implementations. Tufting may increase performances by clever insertion of reinforcement yarn. The infusion by VARI is greatly simplified by the preforming and there is significant time saved. A part of this work presents the production process and specialized tooling. Finally the study deals with costs generated by hand-lay-up and by OSS® to draw conclusions on the economic viability of the process. The CRIAQ COMP-501 project concludes that stitching is interesting for manufacturing and quality management in dry fiber composite parts.

Date	15 Dec 2015
Original language	French
Awarding Institution	École de technologie supérieure
Supervisor	Simon Joncas (Supervisor) & Olivier Vermeersch (Co-supervisor)