Sustainable Marine Structures

Bio-Inspired Meta-Composite Lattice Platforms for Floating Offshore Wind Turbines: Multi-Physics Durability, Hydrodynamic Performance, and Circularity Assessment

Khageshwar Mandal

Department of Mathematics & Statistics, Padma Kanya Multiple Campus (P.K.M.C.), Tribhuvan University (T.U.), Kathmandu 44600, Nepal

Rishav Jha

Department of Science and Technology, MIT Campus, Rajarshi Janak University, Janakpurdham 45600, Nepal

Kameshwar Sahani

Department of Civil Engineering, Kathmandu University (K.U), Dhulikhel 45200, Nepal

Suresh Kumar Sahani

Faculty of Science, Technology, and Engineering, Rajarshi Janak University, Janakpurdham 45600, Nepal

Jay Narayan Jha

Department of Mathematics, Padma Kanya Multiple Campus, Tribhuvan University, Kathmandu 44600, Nepal

DOI: https://doi.org/10.36956/sms.v8i2.3365

Received: 28 May 2026 | Revised: 8 June 2026 | Accepted: 24 June 2026 | Published Online: 30 June 2026

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Abstract

The proposed bio-inspired meta-composite lattice platform (BMCLP) comprises topology-optimized octet-truss lattices with bio-epoxy composite skins reinforced with flax fibre, geometrically based on skeletal architectures of Hexactinellida sponges. A coupled multi-physics framework was developed for a 15 MW floating wind turbine system, integrating finite-element structural analysis, potential-flow hydrodynamics with equivalent Morison calibration for porous lattice members, spectral fatigue assessment with conservative S-N knock-downs for natural fibre composites, Fickian seawater degradation modelling, and a streamlined life cycle assessment (LCA). The BMCLP reduced structural mass by 68.5% while preserving a comparable global stiffness to the steel OC4-DeepCwind benchmark. Hydrodynamic validation against published semi-submersible response amplitude operator (RAO) data showed an 18% reduction in pitch response amplitude under extreme sea state conditions due to wave energy dissipation through the porous lattice; this advantage decreased to 10% under 50 mm marine fouling and 5% under 100 mm heavy fouling. Spectral fatigue analysis using a Joint North Sea Wave Project (JONSWAP) spectrum indicated that the pontoon-to-column joint governed fatigue life, with a 25-year damage index well below unity. Fickian diffusion modelling predicted 78.8% residual compressive strength at 25 years. The LCA demonstrated a 77.6% reduction in global warming potential (GWP) over a 25-year service life, mainly due to bio-based material substitution, avoided steel production, and reduced additive-manufacturing waste. The research links biomimetic structural design, validated multi-physics performance, and circular economy principles, providing a reproducible methodology for low-carbon floating offshore infrastructure.

Keywords: Bio-Inspired Lattice Structures; Floating Offshore Wind Turbines; Meta-Composites; Fatigue Durability; Life Cycle Assessment; Circularity; Hydrodynamic Performance

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