Learning Forum

[kingdsystems]

Hi,

I am trying to model and simulate a subsea pipe on a clay and sandy seabed using AQWA and use the hydrodynamic data obtained to couple the structural.
I have been having issues modeling it. The pipeline will rest on the seabed. Do I have to create a model of the seabed in Modeler or SpaceClaim? 

Please, if anyone has any idea how I can do this with ease, I will be grateful.

Thank you.

[Mike Pettit]

Hello,

Are you modelling the pipe only, or also the pipe-laying vessel? If you are modelling the pipe only, then it may be easier to run your analysis directly in Mechanical, using the Offshore add-on. Offshore allows you to define the ocean environment (waves, current) for the hydrodynamic loading, and Mechanical allows you to create the contacts between the pipe and the seabed, which should also be modelled in the geometry editor. For more information please refer to the online help: 8.2. The Offshore Add-on

Mike

 

[kingdsystems]

Thank you so much for your help. This is a game-changer. I am modeling the pipe only lying on the seabed. I want to simulate the pipe-seabed interactions (effects of the seabed on the pipe). 

However, I'm unsure whether I should model the seabed as a 3D geometry along with the pipe or if there is a provision to enter seabed properties. 

Is there any helpful resource material (video) that can help?

Thank you

[Mike Pettit]

Hello,

You should model the seabed as a 3D geometry, as you will need to scope to it in your contact definitions.

Offshore's Ocean Environment object requires you to set an Ocean Depth value, but this is only used for the wave kinematics (finite water depth formulation). I should also mention that you can define Offshore objects in Static Structural, Transient Structural, Modal and Harmonic Response analyses.

We do have a training course on the Ansys Learning Hub - 'Introduction to Ansys Mechanical for Ocean Loading' - if you have access to that, but I don't know if it covers your specific case.

Mike