Learning Forum

[et22143]

I am trying to carry out a Hydrodynamic pressure analysis of this structure:

It's based on a diffraction analysis of the three floats - which are treated as one structure in Aqwa. The model seems to recognise that there is one hydrodynamic structure, but when I go to solve the model it says 'At least one Hydrodynamic Structure must be defined'. I've tried to add a Hydrodynamic Structure to the model (which from my understanding I should only need if I had more than one structure) to see if that would help, but it requires me to select line bodies (while the floats are only made of surface bodies). I'm also unable to change the Model Type from 'External Surfaces and Line Bodies'. Would anyone be able to help? Many thanks.

[Mike Pettit]

Hello,

When you add the Hydrodynamic Pressure object, a Hydrodynamic Structure object should automatically appear at the same time (though this will not happen if the Hydrodynamic Pressure object can't find any Aqwa files in the first instance). Since Release 2025 R1 you should always include a Hydrodynamic Structure object, even if there is only one structure in the hydrodynamic model.

If the Line Bodies are out of the water, it will not matter to select them in the Hydrodynamic Structure details - there will be no hydrodynamic load applied on them if they're not wet. In other words, selecting them for mapping should not affect the results in this case.

I hope this helps.

Mike