Project Outline

As part of the research project titled “Technology Development for Front-End Engineering Design (FEED) and Detailed Design of Fixed Offshore Substations (OSS) for Offshore Wind Farms,” one of the key research objectives is the development of a configuration concept for a structural health monitoring (SHM) system for the offshore substation substructure.

Since the offshore substation substructure is installed and operated in a marine environment, it is essential to identify its structural behavior under static, dynamic, and fatigue limit states, as well as to determine structurally vulnerable or critical regions, in order to enable effective structural health sensing.

Furthermore, the development of sensing strategies based on behavioral characteristics for each limit state requires three-dimensional finite element analysis (3D FEA) that accounts for the site-specific offshore environmental conditions (such as marine loads and seabed conditions), the substructure geometry in a fluid environment, and the relevant load combinations.

For this purpose, our company was responsible for establishing the finite element analysis base model of the offshore substation substructure.

Scope of Work / Major Tasks

Development of a numerical analysis base model for the offshore substation jacket substructure using SESAM software

 - Generation of the geometry of the offshore substation jacket substructure

 - Definition of design loads and load combinations, including wind, current, and wave loads

 - Definition of member fatigue properties, such as S–N curves

 - Definition of foundation piles and soil conditions

 - Definition of the Topside geometry and structural characteristics of the offshore substation

Verification of model integrity through finite element analyses for various analysis types and limit states

 - Eigenvalue analysis (modal analysis)

 - Static analysis: Ultimate Limit State (ULS) and Serviceability Limit State (SLS)

 - Fatigue analysis: Fatigue Limit State (FLS)

 - Seismic analysis: Ultimate Limit State (ULS) and Accidental Limit State (ALS)