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  #16  
Old 02-07-2013, 10:37 AM
troglodyte troglodyte is offline
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The option of automatic layback estimation comes under Calculation > Line Setup Wizard.

Well, Links are one of the crucial elements required to run the analysis. It's especially true when you have cases where you want to place the umbilical over shapes (like chutes). Defining a spline alone is mostly unlikely to help in these situations.

But there is one thing which you could try. You may run a case where the cable sits perfectly on the chute with the Links taking no tension. Once you achieve this profile, you pull out the X, Y and Z values (from Positions) under Results. I believe you are currently using the Spline statics method? Now you may change the statics method (found in the Line Data) to User Specified. Input the X, Y and Z values -- from the results you obtained earlier -- in the table under "User Specified Starting Shape."

Once you have done the above, you may remove the links from the model. The model should now complete the statics within a second with this modified approach. For other laybacks, you may try increasing/decreasing the X coordinate of the anchored point on seabed. If the layback increments aren't so huge, the XYZ values from previous layback should still work fine for new laybacks. The only catch is here is you must have at least one case with the links in order to obtain the XYZ coordinates.

Hope you find this helpful!

Cheers
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  #17  
Old 02-08-2013, 05:25 AM
c.jack.sparrow c.jack.sparrow is offline
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Join Date: Aug 2012
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Hey!!

Thanks for the post!

Quote:
But there is one thing which you could try. You may run a case where the cable sits perfectly on the chute with the Links taking no tension. Once you achieve this profile, you pull out the X, Y and Z values (from Positions) under Results. I believe you are currently using the Spline statics method? Now you may change the statics method (found in the Line Data) to User Specified. Input the X, Y and Z values -- from the results you obtained earlier -- in the table under "User Specified Starting Shape."
I was trying exactly the same for the last few days and I was getting some decent results that I can trust

What I did was put in several lines (say 4 lines) got a static condition for all of them at the location of the chute. connected a winch. used spline, varied tension and then user specified starting shape.

Works quite well so far.

Just trying to setup the model using Excel now.
I want to create cases where the water depth varies ( say 1m steps, 5m to 25m). that should be possible right?
I am thinking it would be a bit difficult, as the anchor points of the cable for each case will have to change (or cable length or both).
Am I thinking right?

The manual is not a 100% clear how to do the pre processing setup.
I need to specify the cases in water depth in the "create batch script" option right?

Thanks once again!
Cheers
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