Title: WORK-IN-PROGRESS: 3D PRINTED TOOLING AND AUTOMATED EPOXY EXTRUSION FOR HARD SCARF PATCHES

Authors: Jacob W. Walker, Stephen T. Hilton, Florentius Johannes van Zanten, Wout De Backer

DOI: 10.33599/nasampe/s.23.0172

Abstract: The development and operationalization of an Automated Epoxy Extruder (AEE) to lay-up hard patches made from fiber-reinforced composites for use in aircraft repair is presented. This AEE is part of a system and process to manufacture a scarf hard patch using low-cost 3D printed tooling. The wet lay-up process typically generates hazardous epoxy waste, which the AEE seeks to minimize by storing each part, the resin and hardener, in separate dispensers and only mixing them when required via a static mixer. A 3D printed tool for the hard patch wet layup process serves as a template for the dry carbon fiber fabric, and the calculation of total epoxy required is standardized based on predefined fiber-volume ratios. The AEE is mounted to a 3-axis gantry manipulator to automate the nozzle motion across the patch. The technology can help reduce the labor and aircraft downtime needed, by reducing the on-aircraft repair scope, as the hard patch can be manufactured in the depot, without the aircraft present, and then later be bonded to the aircraft. The proposed process can therefore help drive down the cost of composite aircraft repair.

References: [1] X. J. Gong, P. Cheng, S. Aivazzadeh, and X. Xiao, “Design and optimization of bonded patch repairs of laminated composite structures,” Compos Struct, vol. 123, pp. 292–300, May 2015, doi: 10.1016/J.COMPSTRUCT.2014.12.048. [2] A. Baker, “Development of a Hard-Patch Approach for Scarf Repair of Composite Structure,” 2006. [3] A. B. Harman and C. H. Wang, “Improved design methods for scarf repairs to highly strained composite aircraft structure,” Compos Struct, vol. 75, no. 1–4, pp. 132–144, Sep. 2006, doi: 10.1016/J.COMPSTRUCT.2006.04.091. [4] T. D. Breitzman, E. v. Iarve, B. M. Cook, G. A. Schoeppner, and R. P. Lipton, “Optimization of a composite scarf repair patch under tensile loading,” Compos Part A Appl Sci Manuf, vol. 40, no. 12, pp. 1921–1930, Dec. 2009, doi: 10.1016/J.COMPOSITESA.2009.04.033. [5] C. H. Wang and A. J. Gunnion, “Optimum shapes of scarf repairs,” Compos Part A Appl Sci Manuf, vol. 40, no. 9, pp. 1407–1418, Sep. 2009, doi: 10.1016/J.COMPOSITESA.2009.02.009. [6] M. Ridha, V. B. C. Tan, and T. E. Tay, “Traction–separation laws for progressive failure of bonded scarf repair of composite panel,” Compos Struct, vol. 93, no. 4, pp. 1239–1245, Mar. 2011, doi: 10.1016/J.COMPSTRUCT.2010.10.015. [7] S. Psarras, T. Loutas, G. Galanopoulos, G. Karamadoukis, G. Sotiriadis, and V. Kostopoulos, “Evaluating experimentally and numerically different scarf-repair methodologies of composite structures,” Int J Adhes Adhes, vol. 97, p. 102495, Mar. 2020, doi: 10.1016/J.IJADHADH.2019.102495. [8] G. N. Levy, R. Schindel, and J. P. Kruth, “RAPID MANUFACTURING AND RAPID TOOLING WITH LAYER MANUFACTURING (LM) TECHNOLOGIES, STATE OF THE ART AND FUTURE PERSPECTIVES,” CIRP Annals, vol. 52, no. 2, pp. 589–609, Jan. 2003, doi: 10.1016/S0007-8506(07)60206-6. [9] “Large-Format 3D Printer | Raise3D Pro2 Plus | Free Shipping in the US.” https://www.raise3d.com/products/pro2-plus-3d-printer/ (accessed Dec. 08, 2022). [10] C. D. Armenades, E. Al, W. C. Johnson, and T. Raphael, “Mixing Device,” 3,286,992, Nov. 22, 1966 Accessed: Aug. 24, 2022. [Online]. Available: https://patentimages.storage.googleapis.com/31/b2/77/332c56b622bcf4/US3286992.pdf [11] “SIMATIC HMI Basic Panels | SIMATIC HMI Panels | Siemens Global.” https://new.siemens.com/global/en/products/automation/simatic-hmi/panels/basic-panels.html (accessed Dec. 08, 2022). [12] “Duet 3D.” https://www.duet3d.com/Duet3Mainboard6HC (accessed Dec. 20, 2022). [13] “Ultimaker Cura: Powerful, easy-to-use 3D printing software.” https://ultimaker.com/software/ultimaker-cura (accessed Dec. 20, 2022).

Conference: SAMPE 2023

Publication Date: 2023/04/17

SKU: TP23-0000000172

Pages: 12

Price: $24.00