sliding contact in AQWA?

You need to also include your Analysis.dat file (AQWA-LINE). It should be located at :

C:\Documents and Settings\Cercos\Escritorio\Pasquale\18_05_2012\Paper_Naciri.igs_files\dp0\AQW\AQW\AQ\Analysis\Analysis.dat

 

Fenders Application

Hi CWTeebs!


I want to put fenders between two barges.

I seen your file. Yuo define these points on the structure 1:


*additional nodes for fenders
015001 0.000 6.500 10.750
015002 0.000 -6.500 10.750
015003 10.000 6.500 10.750
015004 10.000 -6.500 10.750
015005 50.000 6.500 10.750
015006 50.000 -6.500 10.750
015007 100.000 6.500 10.750
015008 100.000 -6.500 10.750
*reference points for fender normal
015011 0.000 6.500 15.000
015012 0.000 -6.500 15.000
015013 10.000 6.500 15.000
015014 10.000 -6.500 15.000
015015 50.000 6.500 15.000
015016 50.000 -6.500 15.000
015017 100.000 6.500 15.000
015018 100.000 -6.500 15.000
*additional points for transverse fender
015021 0.000 6.250 11.000
015022 0.000 -6.250 11.000
015023 10.000 6.250 11.000
015024 10.000 -6.250 11.000
015025 50.000 6.250 11.000
015026 50.000 -6.250 11.000
015027 100.000 6.250 11.000
015028 100.000 -6.250 11.000
*reference points for transverse fender
015031 0.000 6.500 11.000
015032 0.000 -6.500 11.000
015033 10.000 6.500 11.000
015034 10.000 -6.500 11.000
015035 50.000 6.500 11.000
015036 50.000 -6.500 11.000
015037 100.000 6.500 11.000
015038 100.000 -6.500 11.000


After you define these nodes on the structure 2:


*additional nodes for fenders
015001 0.000 6.500 -1.000
015002 0.000 -6.500 -1.000
015003 10.000 6.500 -1.000
015004 10.000 -6.500 -1.000
015005 50.000 6.500 -1.000
015006 50.000 -6.500 -1.000
015007 100.000 6.500 -1.000
015008 100.000 -6.500 -1.000
*reference points for fender normal
015011 0.000 6.500 -2.000
015012 0.000 -6.500 -2.000
015013 10.000 6.500 -2.000
015014 10.000 -6.500 -2.000
015015 50.000 6.500 -2.000
015016 50.000 -6.500 -2.000
015017 100.000 6.500 -2.000
015018 100.000 -6.500 -2.000


Finally you define:

*FENDERS
14POLY 1.00E9 1.00E10
14FEND 0.25
14FLIN 1 1 5001 2 5001 5011
14FLIN 1 1 5002 2 5002 5012
14FLIN 1 1 5003 5013 2 5003 5013
14FLIN 1 1 5004 5014 2 5004 5014
14FLIN 1 1 5005 5015 2 5005 5015
14FLIN 1 1 5006 5016 2 5006 5016
14FLIN 1 1 5007 5017 2 5007 5017
14FLIN 1 1 5008 5018 2 5008 5018
*FENDERS TO RESTRICT TRANSVERSE MOTION
14POLY 1.00E6 1.00E07
14FEND 0.25
14FLIN 1 1 5021 5031 2 5001 5002
14FLIN 1 1 5022 5032 2 5002 5001
14FLIN 1 1 5023 5033 2 5003 5004
14FLIN 1 1 5024 5034 2 5004 5003
14FLIN 1 1 5025 5035 2 5005 5006
14FLIN 1 1 5026 5036 2 5006 5005
14FLIN 1 1 5027 5037 2 5007 5008
14FLIN 1 1 5028 5038 2 5008 5007


I tried to follow your procedure for me barges (file .zip)
that I applied in the previous post, but I get fenders plaecd
in the wrong way.

If possible, could you please indicate me the process for
the application of fendres.
I simply want define some fenders between the two walls of the barges.

Thank you very much,
Pasquale.

 

AQWA fender problem

Hi CWTeebs!

I annex the complete folder with the Analysis.dat file.

Thank you very much.

 

Hi Garrido,

Sorry for my delayed response. Could you post your CAD files so I can create this in Workbench? In addition to the problem with your fenders there's some other things that need to be fixed (hydrodynamic lid to prevent standing waves between the vessels, addition of hydrodynamic interaction option, etc).

CWTeebs

 

Hi CWTeebs!

Thanks for your kind offer!

I attach a zipped file which contains the CAD (in Rhino format
and IGES format) and the paper that I want to reproduce.

The paper is: TIME DOMAIN SIMULATIONS OF SIDE-BY-SIDE MOORED VESSELS LESSONS LEARNT FROM A BENCHMARK TEST (Author: Mamoun Naciri et al.).

In this paper you have the problem characteristics which are
also used in my workbench file (linked here).

http://dl.dropbox.com/u/51822879/my_Workbench.zip

I inform that I have a 13.0 Ansys version.

We think they are nice materials to work with. The CAD files are not the
original Naciri's ones but we devised hull forms that are quite simillar to those
and whose main dimensions are exactly those, so that results should be at least comparable.

Thank you very much. We are very grateful for your help and we hope you will enjoy the case.

Pasquale.

 

Hi CWTeebs!

If you have problems with FSRU geometry, you can to open the "complete_geometry_modified" file that is attached.
In this file the FSRU geometry has been simplified.

The workbench of this case, with geometry FSRU modified, you can find in the link:

http://dl.dropbox.com/u/51822879/workbench_complete_geometry_modified.zip

I want make time domain analysis with moorings and fenders between the barges (Paper Naciri et al.).

Thanks,
Pasquale.

 

Hi Garrido,

I've started to take a look at your project this morning but didn't finish. You're right, I was having some problems meshing your geometry

I'll hopefully have time to finish this tonight (I'm east coast, USA, it's 2:53PM here right now). In the meantime, I strongly advise you to upgrade to Workbench 14. AQWA integration into Workbench version 13 is terrible, and adding fenders can be done without having to edit the text files in Version 14.

Regardless, I hope to have something working for you tonight.

Cheers,

CWTeebs

 

Hey Garrido,

Just posting to let you know I've been looking at your model. I've done the radiation and diffraction calculations for the interacting structures, using your newest geometry. I've also added the fenders but am running into some rather strange modeling problems for the time domain solution. I'll post it when I get all of the problems sorted out.

CWTeebs

 

Thank for your interest!

I have already installed Workbench 14 and with it, I don't have problems.
I wait yuor informations.

Thank you very much,
Pasquale.

 

Hi Garrido,

Read your PM

 

Try the attached file. Let me know if you want me to delete it after you download. I still get the problem with the vessels moving too far away from each other in the time domain, but, at least the setup is correct. I would move them a bit further away from each other and increase the size of the external lid.

Changes I made:

- Added internal lid to avoid irregular frequencies problem
- Added external lid to limit standing waves
- Did a time domain with RAO based response only (no convolution)
- Added fenders

 

Hi CWTeebs!

Do you know if AQWA allows to get the drift forces, with Far Field Solution?



Thanks.

Kind regards,

Pasquale.

 

Hey man,

Yeah you can do that, just set "near field solution" to No in the analysis settings. Pretty straightforward.

CWTeebs

 

Hi CWTeebs!

Im having a problem in the limitation of the degrees of fredoom in a multibody system.
The description is as follows: I have two bodies, one is fixed in the place and the other one is able to move in heave direction. I was looking the "ansys help", connections paragraph but there isn't the kind of connection that I want. How I can let free the second body only to heave direction? Can I do it from the Workbench?

Thank you very much!

 

Try using DACF in Deck 12, with all but mode 3 (heave) deactivated. You can view the DACF syntax in AQWA Reference.CHM