Hi,
I modeled a 90 ft suction mooring pile as a plate and I modeled the soil inside the pile as a very stiff material. Then I applied the design load at the padeye 58 ft below ground surface. I also created external interface around the pile.
I needed the structural forces around the anchor so I extracted the pressures on the interface every 45 degrees along horizontal using the vertical cross section option. I assumed the same pressure along each 45 degree surface and calculated the forces. Then I transferred these forces from local coordinate system to global coordinate system to calculate the total forces in x and y directions to check the force-balance in horizontal direction. Unfortunately, the forces calculated from the interface are ~15% lower than the forces applied on padeye. I even checked the force balance for another pile length and I am still getting similar type of difference.
Do you think that the procedure that I follow for extracting structural forces are correct? Should I have modeled the suction pile as a rigid body/volume pile? Do you have any other recommendations for me to check? Do you suggest an alternative way for coming up with the structural forces?
Below is the table of Padeye and interface forces. Thank you in advance.