Structural Performance, Manufacturing Feasibility, and Sustainability of a Polyester/Jute Composite Blade for Small Wind Turbines

Natural fiber-reinforced polymer composites have been increasingly investigated for sustainable structural applications, including small wind turbine blades operating under low wind-speed conditions. However, despite their environmental advantages, there is a lack of experimental validation of structural models applied to real aerodynamic blade geometries manufactured with carded natural fibers, whose intrinsic fiber dispersion and microstructural heterogeneity challenge classical laminate-based approaches. The objective of this study is to evaluate the structural performance, modeling validity, and manufacturing feasibility of a small wind turbine blade produced from polyester resin reinforced with carded jute fibers, combining Classical Laminate Theory (CLT), additive-manufactured tooling, vacuum infusion processing, and quasi-static bending experiments. A 3D-printed ABS mold was used to manufacture an S1210 aerodynamic profile, enabling a low-cost and rapid tooling approach aligned with current trends in digital composite prototyping. The blade was structurally modeled using CLT with elastic properties obtained from previous experimental characterization and was experimentally evaluated through quasi-static bending tests instrumented with strain gauges at three spanwise stations. Numerical predictions showed strong agreement with experimental strain measurements, validating the applicability of CLT to carded natural-fiber laminates despite their inherent angular dispersion and microstructural variability. All monitored regions exhibited fully linear elastic behavior, with maximum stresses of approximately 5 MPa—well below the composite tensile strength (~60 MPa)—resulting in a safety factor close to 12. These results confirm the structural reliability, manufacturing feasibility, and sustainability potential of jute-reinforced polyester composites for small wind turbine blades operating in low-wind-speed environments (<2 m/s).