Fiber-reinforced polymers (FRPs) are central to modern wind-energy structures, where durability hinges on fatigue performance under variable-amplitude loading. Within the scope of computational analysis of advanced composite structures, this work presents a concise method and validation for fatigue-damage assessment applied to a representative FRP subcomponent from the wind sector. The method links laboratory coupon S–N curves at different R-ratios, generated under test, to full-field life maps on the subcomponent using a Python workflow built around Ansys PyDPF-Composites [1]. From finite-element analyses, ply-level stresses are extracted in the fiber direction; representative load time histories are processed by rainflow counting; and cumulative damage is computed via Miner’s rule against test-calibrated endurance curves. Verification (V) addresses mesh-refinement effects, stress-component selection, and code-to-code checks for rainflow and endurance-curve routines [2]. Validation (V) uses measured coupon S–N data to predict cycles-to-failure at hot-spots and reports agreement using life-ratio bands and simple error metrics. The demonstration is grounded in the theoretical studies of R.P.L. Nijssen [3], whose work provides the underlying framework for fatigue assessment of composite blades. Similar recommendations are also observed in the FIBREGY Project guidelines and recommendations for using FRP in large offshore wind-turbine platforms [4]. Results show stabilized life maps under refinement, limited hot-spot migration, and sensible sensitivity to R-ratio and mean-stress treatment. The workflow (Ansys Composites PrepPost + Ansys Mechanical + PyDPF-Composites + Fatpack + damage evaluation) is minimal, traceable, and reproducible, enabling practical fatigue V&V for large FRP components.