Post-Forming Limits of Carbon Fibre Reinforced Thermoplastic Tubular Structures in a Rotary Draw Bending Process

Abstract:

This paper presents the post-forming limits of polyamide 6 carbon (CF/PA6) thermoplastic tubes to facilitate design and process optimisation of bent tubular CF/PA6 part manufacturing. Straight CF/PA6 tubes can be post-formed using rotary draw bending at elevated temperature to achieve desired curvatures. Forming limits of the tubes are predicted based on their winding angles, tube geometry, and bending radius, presented as the relation between tube winding angle and bending ratio. Additionally, the corresponding principal shear strain limits are derived from the winding angle limits and tube axial strains. Three sets of CF/PA6 tubes with the configurations of [±30°]₄, [±45°]₄, and [±60°]₄ are heated to 220 °C and post-formed to a bending angle of 90° with a bending ratio of 2. Micro computed tomography imaging is performed to analyse tube geometry after forming to identify forming and failure modes for tubes beyond the forming limits.

• Periodical: Key Engineering Materials (Volume 926)
• Pages: 1379-1386
• DOI: https://doi.org/10.4028/p-fxk5d9
• Online since: July 2022
• Authors: Meng Yuan Li*, Chris Stokes-Griffin, Silvano Sommacal, Paul Compston
• Keywords: CF/PA6, Micro-CT Analysis, Post-Forming, Rotary Draw Bending, Thermoplastic Composite Tube

References

[1] E.C. Claunch, Forecasting on composites – markets, products, and demands, Journal of Textile and Apparel, Technology and Management. 9 (2015) 6.

[2] R.G. Tornero, Composite materials are more present today than ever before in cars, Reinforced Plastics. 59 (2015) 131.

DOI: 10.1016/j.repl.2015.01.004

[3] J. Osborne, Automotive composites – in touch with lighter and more flexible solutions, Metal Finishing. 111 (2013) 26–30.

DOI: 10.1016/s0026-0576(13)70159-4

[4] M. Schäkel, S.M.A. Hosseini, H. Janssen, I. Baran, C. Brecher, Temperature analysis for the laser-assisted tape winding process of multi-layered composite pipes, Procedia CIRP. 85 (2019) 171–176.

DOI: 10.1016/j.procir.2019.09.003

[5] M. Asim, M. Jawaid, N. Saba, Ramengmawii, M. Nasir, M.T.H. Sultan, 1 - Processing of hybrid polymer composites—a review, Hybrid Polymer Composite Materials. (2017) 1–22.

DOI: 10.1016/b978-0-08-100789-1.00001-0

[6] B. Engel, J. Böcking, Bending of fibre-reinforced thermoplastic tubes, The 20th International Conference on Material Forming. (2015) 9.

[7] T. Banno, A. Rashidi, B. Crawford, A.S. Milani, A. Nakai, Development of bend-forming technologies on CFRTP tube, 21st International Conference on Composite Materials. (2019) 6.

[8] S. Eckardt, D. Barfuß, J. Condé-Wolter, M. Gude, V. Würfel, J. Böcking, Study on bend-forming behaviour of thermoplastic tape-braided CFRTP profiles, SAMPE European Conference. (2020) 9.

[9] J. Rousseau, D. Perreux, N. Verdière, The influence of winding patterns on the damage behaviour of filament-wound pipes, Composites Science and Technology. 59 (1999) 1439–1449.

DOI: 10.1016/s0266-3538(98)00184-5

[10] G.R. Myers, A.M. Kingston, S.J. Latham, B. Recur, T. Li, M.L. Turner, et al, Rapidly converging multigrid reconstruction of cone-beam tomographic data, SPIE Optical Engineering + Applications. 9967 (2016).

DOI: 10.1117/12.2238267