Learning Forum

[ADWAIT PANINDRE]

Hello, I am trying to simulate the behavior of the buoy during the installation phase when it is connected to the vessel on the water surface. I wanted to know if is it possible to create a surface fixed structure to which my buoy can be moored or if I can add a fixed point with coordinates above the water surface and connect the cable to it ?

[Erik Kostson]

Hi

Can you describe what software/system you are using (e.g., AQWA) and analysis type (aslo any images supporting your question)?

In that way members of the forum might be able to provide some advice.

Erik

[ADWAIT PANINDRE]

Hello Erik,

I am using ANSYS AQWA and wish to perform hydrodynamic response analysis with two structures: structure A (fixed on the water surface) and Structure B ( Buoy). I am trying to simulate the condition when the buoy is just launched and it's connected to structure A with cable. For this, I can model the Structure B. But I need help modeling Structure A completely fixed on the water surface and the mooring between them.

 

[Shuangxing Du]

(1) If your mooring line is not a nonlinear catenary cable

 You may not need to define Structure A. Instead, just define a fixed point, and link Structure B with this fixed point by your mooring line.

(2) If your mooring line is a nonlinear catenary cable

By using the similar approach of defining Structure B (Buoy), you can define another structure (Structure A) from Geometry then share the geometry with the Hydrodynamic Diffraction analysis.  In Aqwa Editor in Workbench, set Structure Fixity of the Structure A  as "Structure is Fixed in Place", define the connection point on Structure A and a fixed point, define a rigid joint with these two points to link Structure A and the fixed point for the Hydrodynamic Response analysis. Another pair of the connection points should be defined on Structure A ans Structue B for setting up your catenary mooring line. 

In Hydrodynamic Diffraction analysis, if the hydrodynamic interaction between Structure A and Structure B needs to be considered, these two structures should be in an Interaction Structure  Group.