Consolidation Behavior of Fiber Steered Thermoplastic Automated Fiber Placement Preforms

The Thermoplastic Automated Fiber Placement process enables the use of blanks with steered fiber architecture in the stamp forming process chain. Fiber steering however can cause defects, such as undulations and gaps, and therefore might decrease the quality of blanks and final parts. An analysis method was developed to characterize the effect of design and process parameters on gap severity. The gap area increased with decreasing steering radius for both blanks and consolidated laminates. The layup temperature did affect the gap area, while the stamp consolidation pressure had no significant effect. Gap formation mechanisms were identified. The results provide an indication for geometrical limits in respect of the allowed gap ratio. The proposed analysis method might also be applicable to other use cases, such as quality assurance.