RB-FEA Based Digital Twin for Structural Integrity Assessment of Offshore Structures

The reduced basis finite element analysis (RB-FEA) technology was utilized for performing structural analyses of a semisubmersible drilling rig. The digital twin of the drilling rig based on the RB-FEA technology is about 1000 times faster to analyze than a conventional FEA model, without any compromise in the accuracy of the solution. The global model was established by integrating the individual components of the RB-FEA model with associated material properties, loads, and boundary conditions. The software for mapping of the wave loads (generated by software such as WAMIT/WADAM) onto the hull structure of the drilling rig was developed. Time domain strength and fatigue analyses were then performed for the whole structure that also included the highly refined fatigue sensitive regions of the drilling rig. The results from the study demonstrated the efficiency and the accuracy of the RB-FEA based technology. The speedup and level of detail achieved through the RB-FEA technology is a key enabler for the digital twin technology since it enables true condition-based modeling of large and critical assets, allowing all relevant structural details to be included in the model, along with sensor and inspection-based condition data such as cracks, corrosion, and damage due to impact or collision. Asset life extension – enabled by the digital twin and condition-based monitoring using sensor systems – is the key to capitalizing on the value of existing facilities that are operating near (or beyond) their original design life.