Finite Element Analysis (FEA), Subsea & Offshore Structural Engineering

The right analysis at the right time

During the development of Fathoms Modular Recovery System, we were faced with a challenge to undertake global and local studies in a very limited timeframe in order to validate our design and keep the project on track.

Ordinarily, a large structural validation model would be simplified  and would tend to use beam elements, local sub-models and constraint equations. These actions all contribute to increased efficiency by reducing the computing time, allowing for quicker iterations and most commonly a quicker route to the end goal – but each of these steps take preparation time.

Through experience we were able to recognise that the time needed to implement these ‘FEA best practices’ was offset by the computing power available to us in-house. Our analysis machine with 18 core Xeon Gold processor and 192Gb of RAM, coupled with Ansys HPC packs, meant we had the option for analysis of this larger model through a more ‘brute force’ approach.

By meshing the full model using shell idealisations and applying the load cases, with little time spent on analysis model simplification, we were able to achieve a result in the fraction of the time it may have taken us to follow ‘FEA best practice’.

When we reflect on this we can recognise that sometimes the best approach does not always follow the ‘way we always do it’ or ‘industry best practice’ – but it requires us to keep the ultimate goal in mind and work the best solution from what we have in front of us. Will we still have a need for simplification and model refinement? Yes, of course, as there will always be a bigger problem that can’t be solved by following this approach, but by staying adaptive and having the knowledge and experience to apply the right analysis at the right time we can make sure we deliver jobs as efficiently as possible.