Global Multi-Physical Field Coupling Failure Simulation of Submarine Cables under Sudden Loads

Submarine cables, as critical infrastructure for cross-regional power transmission and marine communication, operate long-term in complex and dynamic ocean environments. They are frequently subjected to extreme conditions such as line overloads and short circuits, which pose significant threats to the safe and stable operation of both power and communication systems. However, existing research predominantly focuses on the effects of single physical fields, lacking a systematic understanding of multi-field coupling failure mechanisms. To address this gap, this study develops a three-dimensional thermo-electro-mechanical coupling model based on the COMSOL Multiphysics simulation platform to simulate the distribution and evolution of multi-physical fields under overload conditions. The model analyzes the synergistic failure behavior of the insulation layer under coupled field interactions and investigates the thermal-oxidative aging and thermal stress accumulation in the sheath material induced by overload operation and temperature cycling. The simulation results reveal the evolution patterns of temperature gradients, electric field distortions, and stress-strain distributions across different functional layers of the cable under complex operating conditions, providing a solid foundation for structural design and optimization strategies.