I'm having issues with the Maxsurf Stability module. I’m assessing vessel’s longitudinal strength while it is hoisted, and for that purpose use longitudinal strength option with two points grounding.
The model is set up correctly, (DWL is set at baseline, Single Point is forward hoisting point, etc.), but the results are peculiar. Grounding points are set above DWL, to simulate boat hanging in the air, and graph correctly doesn’t plot any buoyancy loads, but bending moment and shear force plots aren't correct, additionally graph plots grounding only at one point, always the aft one, while grounding force magnitude is in excess of displacement.
And to make things stranger, in profile window bottom Hydromax reports grounding reactions that seem plausible, also when I run Equilibrium analysis, grounding reactions seem to be calculated correctly (same as ones reported in Model window bottom).
Version used is Maxsurf Enteprise Connect Edition V21 Update 02 x64 21.02.00.05 running on Windows 7.
Could you please share some screen captures of your model showing what is happening?
The only thing I could think of here is if the vessel CoG is aft of the aft grounding point then the forward gounding point will have zero weight, however that wouldn't explain why the aft grounding force is greater than the vessel displacement.
I have checked on the stability sample file and it works as expected.
Is there a reason you have set the DWL to baseline? You can just set the grounding points higher.
No, no, it's not that. Anyway, I've browsed trough release notes and found this note on a bug fix.
772718: An error in the grounding reaction forces has been fixed. This error only occurred if the vessel was resting on two grounding points and the error was in the repartition of the grounding reaction at the two points.
Aforementioned text is from the release note for V21.11.00