Amirkabir University of Technology AUT Journal of Mechanical Engineering 2588-2937 10 3 2026 07 01 Nonlinear Free Vibration Optimization of 2D Tri-axial Braided Composite Fan Blade via ANN, Analytical, FEM, and GA Combined Approach 353 378 5974 10.22060/ajme.2026.25311.6264 EN Mortaza Salehian Department of Aerospace Engineering, Amirkabir University of Technology, Tehran, Iran 0009-0004-1439-3260 Hamid Reza Ovesy Department of Aerospace Engineering, Amirkabir University of Technology, Tehran, Iran 0000-0002-1508-5786 Hadi Dabiryan Department of Textile Engineering, Amirkabir University of Technology, Tehran, Iran Journal Article 2025 12 20 This research aims to enhance the hardening behavior of a non-rotating 2D tri-axial braided composite (2DTBC) fan blade, through investigating the backbone curve characteristics. This enhancement raises the blade’s natural frequencies at large oscillation amplitudes, thereby delaying the onset of resonance. A combination of different methods has been employed, including an Artificial Neural Network (ANN), an analytical method, the finite element method (FEM), and a single-objective genetic algorithm (GA). The ANN was used to establish the relationship between the braiding machine parameters and the structural characteristics of the braided fabric. Micromechanical modeling was utilized to determine the mechanical properties of the braided composite. Based on the first-order shear deformation theory (FSDT), the nonlinear free vibration partial differential equations of the composite blade shell were derived using Hamilton's principle. The FEM was employed to solve the differential equations and obtain the corresponding backbone curves. Finally, a single-objective genetic algorithm was deployed to optimize the braided composite structure in order to increase the hardening behavior of the blade. The obtained results demonstrate the viability of the proposed approach. The results indicate that the hardening behavior has increased by a factor of 6.8 compared to the non-optimized case. https://ajme.aut.ac.ir/article_5974_7e1cacfb27da22fb243ff2debf4443a0.pdf