This study investigates the influence of fiber orientation angles on the mechanical performance of 7-layer epoxy/fiberglass composites under tensile loading. Given the growing demand for advanced materials in aerospace, medical, and marine applications, optimizing composite properties—such as Young’s modulus and stress concentration—is critical. Using ABAQUS for finite element simulation and Design Expert software for Design of Experiments (DoE), we analyzed stress distribution and mechanical response across 30 fiber angle configurations. The Response Surface Methodology (RSM) was employed to minimize experimental runs while evaluating three key outputs: longitudinal and transverse Young’s moduli and stress concentration factor (K). ANOVA results confirmed model significance (p < 0.05) with high R² values (>0.98), ensuring robust statistical fits. Quadratic and cubic models were derived for K and Young’s moduli, respectively. Optimization yielded two angle sets: (36.8°, 124°, 28.4°) for balanced E_x (23.82 GPa), E_y (20.86 GPa), and K (2.68); and (83.2°, 131.6°, 61.3°) for minimized K (2.38) with E_y> 10 GPa (28.13 GPa). These results demonstrate that fiber angles critically govern anisotropic behavior, with specific orientations reducing stress concentrations by up to 12% while maintaining stiffness.
Yang, G., Park, M., & Park, S. J. (2019). Recent progresses of fabrication and characterization of fibers-reinforced composites: A review. Composites Communications, 14, 34–42. doi:10.1016/j.coco.2019.05.004.
Pendhari, S. S., Kant, T., & Desai, Y. M. (2008). Application of polymer composites in civil construction: A general review. Composite Structures, 84(2), 114–124. doi:10.1016/j.compstruct.2007.06.007.
Hasan, M., Zhao, J., & Jiang, Z. (2019). Micromanufacturing of composite materials: A review. International Journal of Extreme Manufacturing, 1(1), 12004. doi:10.1088/2631-7990/ab0f74.
Khayal, O. M. E. S. (1998). Updated Curriculum Vitae. PhD Thesis, Sudan University of Science and Technology, Khartoum, Sudan.
Sinha, A. K., Narang, H. K., & Bhattacharya, S. (2020). Mechanical properties of hybrid polymer composites: a review. Journal of the Brazilian Society of Mechanical Sciences and Engineering, 42(8), 431. doi:10.1007/s40430-020-02517-w.
Nziu, P. K., & Masu, L. M. (2019). Cross bore geometry configuration effects on stress concentration in high-pressure vessels: a review. International Journal of Mechanical and Materials Engineering, 14(1), 6. doi:10.1186/s40712-019-0101-x.
Rezaeepazhand, J., & Jafari, M. (2005). Stress analysis of perforated composite plates. Composite Structures, 71(3–4), 463–468. doi:10.1016/j.compstruct.2005.09.017.
Özaslan, E., Yetgin, A., Acar, B., & Güler, M. A. (2021). Damage mode identification of open hole composite laminates based on acoustic emission and digital image correlation methods. Composite Structures, 274, 114299. doi:10.1016/j.compstruct.2021.114299.
Hsu, C. W., & Hwu, C. (2021). A special boundary element for holes/cracks in composite laminates under coupled stretching-bending deformation. Engineering Analysis with Boundary Elements, 133, 30–48. doi:10.1016/j.enganabound.2021.08.016.
Bayati Chaleshtari, M. H., & Khoramishad, H. (2022). Investigation of the effect of cutout shape on thermal stresses in perforated multilayer composites subjected to heat flux using an analytical method. European Journal of Mechanics, A/Solids, 91, 104412. doi:10.1016/j.euromechsol.2021.104412.
Rahmouni, F., Elajrami, M., Madani, K., & Campilho, R. D. S. G. (2023). Isogeometric analysis of stress concentrations and failure strength in composite plates with circular holes using RHT-splines. European Journal of Mechanics-A/Solids, 99, 104904. doi:10.1016/j.euromechsol.2022.104904.
Duan, S., Zhang, Z., Wei, K., Wang, F., & Han, X. (2020). Theoretical study and physical tests of circular hole-edge stress concentration in long glass fiber reinforced polypropylene composite. Composite Structures, 236, 111884. doi:10.1016/j.compstruct.2020.111884.
Sun, J., Jing, Z., Wu, J., Wang, W., Zhang, D., & Zhao, J. (2020). Strain rate effects on dynamic tensile properties of open-hole composite laminates. Composites Communications, 19, 226–232. doi:10.1016/j.coco.2020.04.004.
Patel, R. H., & Patel, B. P. (2022). Effect of various discontinuities present in a plate on stress concentration: a review. Engineering Research Express, 4(3), 32001. doi:10.1088/2631-8695/ac8c1b.
Dhand, V., Mittal, G., Rhee, K. Y., Park, S. J., & Hui, D. (2015). A short review on basalt fiber reinforced polymer composites. Composites Part B: Engineering, 73, 166–180. doi:10.1016/j.compositesb.2014.12.011.
Rahman, R., & Zhafer Firdaus Syed Putra, S. (2019). Tensile properties of natural and synthetic fiber-reinforced polymer composites. Mechanical and Physical Testing of Biocomposites, Fibre-Reinforced Composites and Hybrid Composites, 81–102, Woodhead Publishing, Sawston, United Kingdom. doi:10.1016/b978-0-08-102292-4.00005-9.
Prashanth, S., Subbaya, K. M., Nithin, K., & Sachhidananda, S. (2017). Fiber reinforced composites-a review. J. Mater. Sci. Eng, 6(03), 2-6.
Le, T. M., & Pickering, K. L. (2015). The potential of harakeke fibre as reinforcement in polymer matrix composites including modelling of long harakeke fibre composite strength. Composites Part A: Applied Science and Manufacturing, 76, 44–53. doi:10.1016/j.compositesa.2015.05.005.
Luo, H., Wang, H., Zhao, Z., Xue, H., & Li, Y. (2023). Experimental and numerical investigation on the failure behavior of Bouligand laminates under off-axis open-hole tensile loading. Composite Structures, 313, 116932. doi:10.1016/j.compstruct.2023.116932.
Kumar, S. A., Rajesh, R., & Pugazhendhi, S. (2020). A review of stress concentration studies on fibre composite panels with holes/cutouts. Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications, 234(11), 1461–1472. doi:10.1177/1464420720944571.
Sirmour, S., Kumar, U., Chandrakar, H., & Gupta, N. (2019). Open Hole Testing Methods for Different Materials: A Review. IOP Conference Series: Materials Science and Engineering, 561(1), 012037. doi:10.1088/1757-899x/561/1/012037.
Konica, S., & Sain, T. (2023). Phase-field fracture modeling for unidirectional fiber-reinforced polymer composites. European Journal of Mechanics, A/Solids, 100, 105035. doi:10.1016/j.euromechsol.2023.105035.
Altin Karataş, M., & Gökkaya, H. (2018). A review on machinability of carbon fiber reinforced polymer (CFRP) and glass fiber reinforced polymer (GFRP) composite materials. Defence Technology, 14(4), 318–326. doi:10.1016/j.dt.2018.02.001.
Van Quy, H. O., & Nguyen, S. T. T. (2019). Experimental Analysis of Coir Fiber Sheet Reinforced Epoxy Resin Composite. IOP Conference Series: Materials Science and Engineering, 642(1), 12007. doi:10.1088/1757-899X/642/1/012007.
Çuvalci, H., Erbay, K., & İpek, H. (2014). Investigation of the Effect of Glass Fiber Content on the Mechanical Properties of Cast Polyamide. Arabian Journal for Science and Engineering, 39(12), 9049–9056. doi:10.1007/s13369-014-1409-8.
Azmi, N. N., Mohd Radi, M. B. A., Muhammad Taufik, M. H. N., Adnan, N., Minhuaazam, L. N., & Mahmud, J. (2023). The effects of open hole and fiber orientation on Kevlar/Epoxy and Boron/Epoxy composite laminates under tensile loading. Materials Today: Proceedings, 75, 169–172. doi:10.1016/j.matpr.2022.11.220.
Marinkovic, D., & Zehn, M. (2019). Survey of finite element method-based real-time simulations. Applied Sciences (Switzerland), 9(14), 2775. doi:10.3390/app9142775.
Toubal, L., Karama, M., & Lorrain, B. (2005). Stress concentration in a circular hole in composite plate. Composite Structures, 68(1), 31–36. doi:10.1016/j.compstruct.2004.02.016.
Uy, M., & Telford, J. K. (2009). Optimization by Design of Experiment techniques. 2009 IEEE Aerospace Conference, 1–10. doi:10.1109/aero.2009.4839625.
Chelladurai, S. J. S., K., M., Ray, A. P., Upadhyaya, M., Narasimharaj, V., & S., G. (2021). Optimization of process parameters using response surface methodology: A review. Materials Today: Proceedings, 37, 1301–1304. doi:10.1016/j.matpr.2020.06.466.
Mohamed, B., Khaoula, A., & Leila, B. (2023). Effect of the Fibers Orientation of the Different Types of Composite Plates Notched of U-Shape Repaired by Composite Patch. Materials Research, 26, 20220302. doi:10.1590/1980-5373-MR-2022-0302.
Yunardi, Y., Zulkifli, Z., & Masrianto, M. (2011). Response Surface Methodology Approach to Optimizing Process Variables for the Densification of Rice Straw as a Rural Alternative Solid Fuel. Journal of Applied Sciences, 11(7), 1192–1198. doi:10.3923/jas.2011.1192.1198.
Motamedi, M. , & Elahifar, M. (2025). Effect of layer angle on mechanical properties of epoxy-fiberglass composite. Contributions of Science and Technology for Engineering, 2(2), 9-16. doi: 10.22080/cste.2025.28948.1027
MLA
Mohsen Motamedi; Mohammad Elahifar. "Effect of layer angle on mechanical properties of epoxy-fiberglass composite", Contributions of Science and Technology for Engineering, 2, 2, 2025, 9-16. doi: 10.22080/cste.2025.28948.1027
HARVARD
Motamedi, M., Elahifar, M. (2025). 'Effect of layer angle on mechanical properties of epoxy-fiberglass composite', Contributions of Science and Technology for Engineering, 2(2), pp. 9-16. doi: 10.22080/cste.2025.28948.1027
CHICAGO
M. Motamedi and M. Elahifar, "Effect of layer angle on mechanical properties of epoxy-fiberglass composite," Contributions of Science and Technology for Engineering, 2 2 (2025): 9-16, doi: 10.22080/cste.2025.28948.1027
VANCOUVER
Motamedi, M., Elahifar, M. Effect of layer angle on mechanical properties of epoxy-fiberglass composite. Contributions of Science and Technology for Engineering, 2025; 2(2): 9-16. doi: 10.22080/cste.2025.28948.1027
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