Topology Optimization of a Parallel-Leg Jacket Substructure for a 10 MW Offshore Wind Turbine

This study proposes a parallel-leg jacket concept for a 10 MW offshore wind turbine and employs density-based topology optimization as a concept-stage load-path guidance tool to develop a lightweight tubular jacket configuration. In contrast to conventional battered-leg jacket designs, the proposed configuration adopts vertical parallel legs to provide a more regular geometric arrangement. A SIMP-based topology-optimization approach is applied to the proposed parallel-leg design domain to identify efficient material distribution and dominant load-transfer paths while eliminating low-stress regions. The topology-optimization-guided layout is subsequently reconstructed into a tubular jacket substructure for structural evaluation. Compared with the reference jacket design, the reconstructed parallel-leg jacket exhibits a 5.8% reduction in structural mass and a 34.8% reduction in maximum global displacement, from 135.85 mm to 88.62 mm, under the configuration-specific system-level assessment. The reduction in peak von Mises stress is comparatively modest, at approximately 2.3%, from 149.99 MPa to 146.6 MPa and slightly improved low-order modal characteristics. The comparison is conducted at the system level using configuration-specific IEC-based extreme loading conditions generated in DNV Bladed™. Overall, the topology-optimization-guided reconstructed parallel-leg jacket shows the feasibility of applying topology-based load path identification for developing a concept-stage alternative for offshore wind turbine support structures.