Title: Modeling the Impact of Tool Geometry on Thickness Changes during the Thermoforming of a Thermoplastic Composite

Authors: Kari D. White, James A. Sherwood

DOI: 10.33599/nasampe/s.24.0189

Abstract: Thermoforming is an economically attractive process for transforming a flat sheet of thermoplastic composite material into a complex shape. For thick parts, a two-step process is typically used. The two-step process consists of a preform step that forms the laminates to near-net-shape ply stacks and of a subsequent consolidation step of pressure and heat to join the preforms into a final part. During the preform step, a binder ring is used to induce in-plane tension to mitigate wrinkling and to drive shear as the dominant mode of deformation. The material increases in thickness as it undergoes in-plane shear to conform to the preform shape. The degree of shear can vary over the part, creating variations in thickness and subsequent challenges with uniform consolidation. While material attributes and processing parameters are critical in successful preforming, the tool geometry may also be exploited to affect part quality. This paper presents the use of a discrete finite element approach to simulate the preforming of a UHMWPE cross-ply thermoplastic and how this modeling can be used in the design of tooling that will mitigate wrinkling and reduce the variation in thickness changes over the formed part.

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Conference: SAMPE 2024

Publication Date: 2024/05/20

SKU: TP24-0000000189

Pages: 13

Price: $26.00