W.A. Wirawan, A. Sabitah, M. Mushlimin, K. Boimau, E. Widodo, R.A. Ilyas
This study aimed to develop carbon fiber-epoxy composites with improved mechanical performance for industrial applications requiring lightweight and high-strength materials. The mechanical behavior of these composites is strongly influenced by laminate configuration and fiber orientation, which govern tensile strength, stiffness, and damage resistance. The composites were fabricated by vacuum resin infusion using different laminate numbers and fiber orientations, followed by tensile, flexural, impact, and hardness testing. Increasing the number of layers in the 0°/90° orientation increased the tensile strength from 386.192 MPa for 2LCF-0/90 to 485.922 MPa for 8LCF-0/90, corresponding to a 25.8% improvement. In the same eight-layer configuration, the 0°/90° laminate exhibited a tensile strength 92.0% higher than that of the 45°/45° laminate (253.076 MPa). The highest flexural strength was observed for 2LCF-0/90 at 1304.32 MPa; however, this value decreased to 496.821 MPa for 8LCF-0/90, representing a 61.9% reduction, indicating that excessive layer addition may impair bending performance due to interlaminar defects and stress concentration. In contrast, the absorbed impact energy increased markedly from 0.396 J to 16.585 J, while ShoreD hardness increased from 78.000 HD to 84.000 HD, corresponding to a 7.7% increase. These findings confirm that laminate design plays a critical role in determining the mechanical performance of carbon fiber-epoxy composites. Although increasing the number of layers improves tensile strength, impact resistance, and hardness, excessive layering may reduce flexural performance and compromise structural reliability under tensile loading because of imperfect interlayer bonding. © 2026, Wirawan W. A., Sabitah A., Mushlimin M., Boimau K., Widodo E., Ilyas R. A.
Mechanical Engineering Department, Faculty of Vocational Studies, Universitas Negeri Surabaya, Kampus Ketintang Jl., Ketintang, Surabaya, 60231, Indonesia; Mechanical Engineering Department, Politeknik Negeri Banjarmasin, Jl. Brig Jend. Hasan Basri, Pangeran, Kec. Banjarmasin Utara, Kalimantan Selatan, Kota Banjarmasin, 70124, Indonesia; Mechanical Engineering Department, Universitas Khairun, Yusuf Abdurrahman St., Ternate, Gambesi, 97719, Indonesia; Universitas Muhammadiyah Sidoarjo, 25, Jl. Raya Gelam St., Sidowayah, Celep, Kec. Sidoarjo, Kabupaten Sidoarjo, Jawa Timur, 61215, Indonesia; Mechanical Engineering Department, Faculty of Science and Engineering, Universitas Nusa Cendana, Jl. Matani Raya, Lasiana, Kec. Klp. Lima, Nusa Tenggara Tim., Kota Kupang, 85361, Indonesia; Department of Chemical Engineering, Faculty of Chemical and Energy Engineering, Universiti Teknologi Malaysia, Johor, Johor Bahru, 81310, Malaysia
