Modeling and parametric analysis of tow-steered composites with manufacturing defects using unstructured meshing technique

Tow-steered composites enable spatial stiffness tailoring through curvilinear fiber paths and offer significant performance improvements over conventional straight-fiber composites. However, their manufacturing via Automated Fiber Placement inherently introduces defects due to spatial thickness variations, which influence structural response. This study presents a finite element framework for the modeling and parametric analysis of a single tow-steered composite lamina constructed using the Overlap Method, while explicitly accounting for the manufacturing defects. A novel unstructured meshing strategy is developed to conform element boundaries to discrete tow overlap geometries, enabling accurate representation of nominal and overlap regions. Linear fiber-angle variation is employed to generate curvilinear paths, and a parametric study is conducted over a wide range of tow-steered configurations. Buckling load factor is evaluated and compared against straight-fiber baselines. Results demonstrate that appropriately selected tow-steered configurations can significantly outperform constant-stiffness laminas, while also revealing strong sensitivity of structural performance to overlap topology and fiber path parameters. The proposed modeling approach provides an efficient tool for high-fidelity parametric investigation of variable stiffness composites.