About this Abstract |
Meeting |
2024 ASC Technical Conference, US-Japan Joint Symposium, D30 Meeting
|
Symposium
|
2024 ASC Technical Conference, US-Japan Joint Symposium, D30 Meeting
|
Presentation Title |
Stretch Steering of Aligned Discontinuous Fiber Tapes using Laser Tape Placement: Minimizing Placement Defects |
Author(s) |
Lukas Fuessel, Alexander Legenstein, John W. Gillespie |
On-Site Speaker (Planned) |
Lukas Fuessel |
Abstract Scope |
The steering of carbon fiber tapes enables topology optimization and weight reduction of composite parts. Continuous fiber laminates are limited by a minimal steering radius (MSR) of around 1600-2000 mm for a 12.7 mm wide tape due to excessive defect formation such as folds on the inner radius subjected to compression. Aligned discontinuous fiber prepreg has been fabricated from Tailored Universal Feedstock for Forming (TuFF) preforms comprised of 3mm IM7 fiber and polyeitherimide (PEI) matrix at 57% fiber volume fraction. An order of magnitude reduction in minimum steering radius of defect-free TuFF has been demonstrated on 12.7mm wide on a 100mm radius compared to continuous fiber tape. This is possible by adding a membrane tension strain to the bending strain induced by steering. A photogrammetry-based digital image correlation method has been used to measure the in-plane strain field in the steered tape enabling validation of the mechanisms of stretch steering. In addition, the statistical variation in the strain field is used to establish a process window that allows at most 1% of defects on either the inner radius (compression) and outer radius (tension). This analysis shows that 12.7mm wide TuFF tape with an initial stretch strain of 21.5% can be steered at an MSR of 33mm. This methodology can also be applied to narrower tape widths to achieve even lower MSR. This further highlights the design freedom of TuFF using in-situ stretch steering for tape placement that significantly improves process capability for topology optimization for highly tailored parts. |
Proceedings Inclusion? |
Definite: Post-meeting proceedings |