A review of failure mechanisms, simulation and testing methods in the marine transmission systems context.

Abstract

The operational viability of offshore renewable energy systems is constrained by the reliability of gear transmission assemblies. This paper provides an exhaustive review of state-of-the-art literature concerning marine gearing, synthesising the multi-physics synergies between mechanical loading and environmental aggression. This review characterises the technical evolution from deterministic industrial standards toward high-fidelity frameworks that account for the coupling of contact fatigue, progressive wear, and electrochemical corrosion. Key focuses include the modelling of emerging subsurface-initiated modes, such as Tooth Interior Fatigue Fracture (TIFF), through depth-dependent material property gradients and multiaxial fatigue criteria. The review evaluates advanced numerical strategies, including the Extended Finite Element Method (XFEM) for autonomous crack path prediction and Rigid-Flexible Multibody Dynamics (MBS) for resolving system-level responses to stochastic Non-Torque Loads (NTLs). Furthermore, experimental validation protocols within the Very High Cycle Fatigue (VHCF) regime and quantitative non-destructive diagnostics, such as Acoustic Emission (AE), are assessed for their role in calibrating Digital Twin and Prognostic Health Management (PHM) frameworks. Finally, considerations are proposed to guide future research, linking microscopic material integrity and macroscopic system reliability for the next generation of offshore renewable energy assets.