Automated Fibre Placement (AFP) allows for efficient deposition of composite prepreg materials at large scale in a reliable and reproducible way, while keeping human effort to a minimum. However, the technique is not perfectly suited to manufacturing small/medium parts with complex geometries. Deviation between as-designed and as-manufactured parts is almost inevitable, as is the occurrence of process-induced defects. In this study, an alternative design and manufacturing process is proposed. Instead of depositing composite tapes directly onto the complex mould, a flat tailored preform made from steered fibre tows is created first, and then the flat preform is subsequently formed into a 3D complex shape. The fibre path in the flat tailored preform is derived from a new virtual ‘un-forming’ process of a complex 3D part design with target fibre paths. To demonstrate the process, a small doubly curved composite part was un-formed. Fibre-steered tailored preforms were created using the continuous tow shearing (CTS) technique and then formed into the target shape using double diaphragm forming. The as-manufactured part was compared with the as-designed part as well as a part manufactured from straight fibre prepreg. The results demonstrated the feasibility of the virtual un-forming process and the potential of proposed manufacturing route.
This work was funded by the feasibility study “Virtual un-manufacturing of fibre-steered preforms for complex geometry composites” of the EPSRC (The Engineering and Physical Sciences Research Council, United Kingdom) Future Composites Manufacturing Hub ( EP/P006701/1 ) and the EPSRC platform grant “SIMulation of new manufacturing PROcesses for Composite Structures (SIMPROCS)”, ( EP/P027350/1 ).
© 2021 The Authors
- Structural composites
- Polymer-matrix composites (PMCs)
- Finite element analysis (FEA)
- Automated Fibre Placement