Title: Microstructure-Based Homogenization of Elastic Properties in Additively Manufactured Thermoplastic Composites

Authors: Md Tareq Hassan, Samiul Alam, Juhyeong Lee

DOI: 10.33599/nasampe/s.25.0113

Abstract: Additive manufacturing (AM) of fiber-reinforced thermoplastic composites has emerged as a promising technology, enabling the fabrication of lightweight, complex geometries with reduced material waste and lower production costs. Among various AM methods, composites-based additive manufacturing (CBAM) has gained attention for its rapid prototyping and producing parts with enhanced mechanical properties. Regardless of these benefits, CBAM-printed composites may inherently possess a certain level of defects introduced during the manufacturing process, such as voids, microcracks, and non-uniform porosity. To address these challenges, understanding the relationship between microstructural characteristics and effective mechanical properties is critical. Micro-computed tomography (μCT) is a powerful technique for characterizing the internal microstructure (i.e., fiber and porosity size, distribution) of a composite. This study presents a microstructure-based micromechanical finite element (FE) model predicting the effective mechanical properties of non-woven carbon fabric (CF) reinforced nylon (PA-12) composites, fabricated using CBAM. Three distinct RVE models of various sizes were developed, each capturing μCT image from different locations, and used to determine the effective properties of CBAM-printed CF/PA-12 specimens. This work aims to develop an efficient micromechanical framework to understand the relationship between microstructural characteristics and effective properties of additively manufactured thermoplastic composites.

References: [1] A. C. Garg, “Delamination—a damage mode in composite structures,” Engineering Fracture Mechanics, vol. 29, no. 5, pp. 557–584, Jan. 1988, doi: 10.1016/0013-7944(88)901816. [2] A. Knopp, E. Funck, A. Holtz, and G. Scharr, “Delamination and compression-afterimpact properties of z-pinned composite laminates reinforced with circumferentially notched zpins,” Composite Structures, vol. 285, p. 115188, Apr. 2022, doi: 10.1016/j.compstruct.2022.115188. [3] “The Edge-Hyper-Wiener Index of Zigzag Single-Walled Nanotubes,” Polycyclic Aromatic Compounds, Mar. 2022, doi: 10.1080/10406638.2022.2030764. [4] I. Palaci, S. Fedrigo, H. Brune, C. Klinke, M. Chen, and E. Riedo, “Radial Elasticity of Multiwalled Carbon Nanotubes,” Phys. Rev. Lett., vol. 94, no. 17, p. 175502, May 2005, doi: 10.1103/PhysRevLett.94.175502. [5] M.-F. Yu, T. Kowalewski, and R. S. Ruoff, “Investigation of the Radial Deformability of Individual Carbon Nanotubes under Controlled Indentation Force,” Phys. Rev. Lett., vol. 85, no. 7, pp. 1456–1459, Aug. 2000, doi: 10.1103/PhysRevLett.85.1456. [6] M.-F. Yu, O. Lourie, M. J. Dyer, K. Moloni, T. F. Kelly, and R. S. Ruoff, “Strength and Breaking Mechanism of Multiwalled Carbon Nanotubes Under Tensile Load,” Science, vol. 287, no. 5453, pp. 637–640, Jan. 2000, doi: 10.1126/science.287.5453.637. [7] K. N. Kudin, G. E. Scuseria, and B. I. Yakobson, “C2F, BN, and C nanoshell elasticity from ab initio computations,” Phys. Rev. B, vol. 64, no. 23, p. 235406, Nov. 2001, doi: 10.1103/PhysRevB.64.235406. [8] D. Askari and M. N. Ghasemi-Nejhad, “Effects of Vacancy Defects on Mechanical Properties of Graphene/Carbon Nanotubes: A Numerical Modeling,” Journal of Computational and Theoretical Nanoscience, vol. 8, no. 4, pp. 783–794, Apr. 2011, doi: 10.1166/jctn.2011.1753. [9] D. Askari and M. N. Ghasemi-Nejhad, “Generally cylindrical orthotropic constitutive modeling of matrix-filled carbon nanotubes: Transverse mechanical properties and responses,” Jnl of Sandwich Structures & Materials, vol. 22, no. 7, pp. 2330–2363, Oct. 2020, doi: 10.1177/109963621879537. [10] A. L. Kalamkarov, D. Askari, V. P. Veedu, and M. N. Ghasemi-Nejhad, “Generally Cylindrical Orthotropic Constitutive Properties Modeling of Matrix-filled Single-walled Nanotubes: Axial Mechanical Properties,” Journal of Composite Materials, vol. 41, no. 6, pp. 757–779, Mar. 2007, doi: 10.1177/0021998306067018. [11] R. Sritharan and D. Askari, “Analytical Modeling Of A 3-Phase Nanocomposite Cylindrical Unit Cell With Orthotropic Constituents,” in CAMX 2023, Atlanta, GA: NA SAMPE, 2023. doi: 10.33599/nasampe/c.23.0177. [12] A. Lekawa-Raus, J. Patmore, L. Kurzepa, J. Bulmer, and K. Koziol, “Electrical Properties of Carbon Nanotube Based Fibers and Their Future Use in Electrical Wiring,” Advanced Functional Materials, vol. 24, no. 24, pp. 3661–3682, 2014, doi: 10.1002/adfm.201303716. [13] A. Kokabi, M. Salehiyoun, and A. Zarini, “Electronic characteristics of SbBi binary nanoflakes,” Computational Condensed Matter, vol. 30, p. e00639, Mar. 2022, doi: 10.1016/j.cocom.2022.e00639. 15[14] X. Zhangyang, L. Liu, F. Lu, and J. Tian, “Structural, electrical and optical properties of InxGa1-xN nanowires photocathode,” Applied Surface Science, vol. 593, p. 153394, Aug. 2022, doi: 10.1016/j.apsusc.2022.153394. [15] R. Vijayan, A. Ghazinezami, S. R. Taklimi, M. Y. Khan, and D. Askari, “The geometrical advantages of helical carbon nanotubes for high-performance multifunctional polymeric nanocomposites,” Composites Part B: Engineering, vol. 156, pp. 28–42, Jan. 2019. [16] R. Sritharan, S. Taklimi, A. Ghazinezami, and D. Askari, “Mechanical properties improvement of polymeric nanocomposites reinforced with chemically treated helical carbon nanotubes: Influence of sonication time and molarities of nitric-sulfuric-hydrochloric acids,” in CAMX 2018, Anaheim, CA: NA SAMPE, 2018, pp. 1–14. [17] R. Sritharan, S. Taklimi, A. Ghazinezami, and D. Askari, “Chemically Treated Helical Carbon Nanotubes Reinforcement for Polymeric Nanocomposites: Influence of Sonication Time and Treatment Sequence with a Mixture of Nitric-Sulfuric-Hydrochloric Acids at High Molarities,” in CAMX 2024, San Diego, CA: NA SAMPE, 2024. [18] R. Sritharan and D. Askari, “Enhancing the short-beam strength of composite laminates using helical carbon nanotubes,” Composites Part B: Engineering, vol. 221, p. 108999, Sep. 2021. [19] R. Sritharan and D. Askari, “Improvement of the tensile properties of laminated composites reinforced with Heli-Coil forms of carbon nanotubes,” Polymer Composites, vol. 44, no. 10, pp. 7070–7083, 2023, doi: 10.1002/pc.27619. [20] R. Sritharan and D. Askari, “Enhancement of the Mechanical Properties And Bonding of Composite Laminates and Assemblies Using Carbon Nano-Coils,” in CAMX 2022, Anaheim, CA: NA SAMPE, 2022. doi: 10.33599/nasampe/c.22.0137. [21] R. Sritharan and D. Askari, “Effects of Helical Carbon Nanotubes on Mechanical Performance of Laminated Composites and Bonded Joints,” SAE Int. J. Adv. & Curr. Prac. in Mobility, vol. 2, no. 3, Art. no. 2020-01–0029, Mar. 2020, doi: 10.4271/2020-01-0029. [22] R. Sritharan and D. Askari, “Interlaminar Properties Improvement of Nanocomposites Using Coiled Nanomaterials,” in SAE AeroTech, Warrendale, PA: SAE International, Mar. 2021. doi: 10.4271/2021-01-0027. [23] D. Askari, S. R. Taklimi, and A. Ghazinezami, “Helical carbon nanotubes,” US20190382269A1, Dec. 19, 2019. Available: https://patents.google.com/patent/US20190382269A1/en [24] D. Askari, “Nanocomposites with interlocking nanostructures,” US20190308905A1, Oct. 10, 2019. Available: https://patents.google.com/patent/US20190308905A1/en [25] M. N. G. Nejhad, V. P. Veedu, A. Yuen, and D. Askari, “Polymer matrix composites with nano-scale reinforcements,” US7658870B2, Feb. 09, 2010. Available: https://patents.google.com/patent/US7658870B2/en [26] D. Askari, V. P. Veedu, and M. N. Ghasemi-Nejhad, “A Theoretical Investigation on Chirality Dependence of Single-Walled Carbon Nanotubes Thermal Conductivity,” Nano Communications, vol. 1, no. 1, pp. 22–30, Jun. 2014, doi: 10.1166/nano.2014.1009. [27] “Standard Test Methods for Flexural Properties of Unreinforced and Reinforced Plastics and Electrical Insulating Materials.”. Available: https://www.astm.org/d0790-17.html [28] “Standard Test Method for Lap Shear Adhesion for Fiber Reinforced Plastic (FRP) Bonding.”. Available: https://www.astm.org/d5868-01r14.html [29] “Standard Test Method for Short-Beam Strength of Polymer Matrix Composite Materials and Their Laminates.”. Available: https://www.astm.org/d2344_d2344m-16.html 16[30] “Standard Test Method for Tensile Properties of Polymer Matrix Composite Materials.”. Available: https://www.astm.org/d3039_d3039m-17.html [31] “EPON 815C,” Miller-Stephenson Chemicals. Available: stephenson.com/product/epon-815c/ [32] https://miller“EPIKURE 3282 | Epikure 3282 Curing Agent | Modified Aliphatic Amine,” MillerStephenson Chemicals. Available: https://miller-stephenson.com/product/epikure-3282/ [33] R. Sritharan and D. Askari, “A design of experiment study to investigate the effects of hardener concentration, stirring time, and air bubbles on the tensile strength of epoxy resin,” Journal of Elastomers & Plastics, vol. 54, no. 7, pp. 1129–1147, Nov. 2022. [34] “Helical Multi Walled Carbon Nanotubes,” Cheap Tubes. Available: https://cheaptubes.com/product-category/helical-multi-walled-carbon-nanotubes/ [35] “3D Surface Profiler | KEYENCE America.”. Available: https://www.keyence.com/products/microscope/laser-microscope

Conference: SAMPE 2025

Publication Date: 2025/05/19

SKU: TP25-0000000113

Pages: 17

Price: $34.00