Questions about the modes of the tower

Dear Prof Jonkman:

 Several days ago, I asked you some quetions about the mode shapes of the tower. In order to calculate the mode shapes of the tower I need some paramaters about the tower top mass. You give me a link, and I use the tower top results there to calculate the tower mode shapes. The tower is as same as the NREL 5 MW onshore tower and the tower top paramters are:

3.500003109E+005 tip_mass
-0.4137754432 cm_loc
1.9669893542 cm_axial
4.370E7 ixx_tip
2.353E7 iyy_tip
2.542E7 izz_tip
0. ixy_tip
1.169E6 izx_tip
0. iyz_tip

I use the Matlab to get the coefficients of the mode shapes and compared the results with the FAST tower input file of the NREL 5 MW onshore wind turbine. But except the S-S first mode shape the others are not very well and there is a big difference between the second mode shapes. Can you give me some help?
Thans a lot!

Best regards,
Wenhua.Wang

Dear Wenhua,

I answered a very similar question in my Nov 07, 2012 post in the forum topic found here: BModes : Input parameters about tower support subsystem.

Best regards,

Dear Prof Jonkman:
In order to get the mode shapes of the tower, I refered to viewtopic.php?f=4&t=742. I usse the FAST-to-ADAMS preprocessor to built an ADAMS model, the model file name is hw5mw_ADAMS.adm. I use the ADAMS view to view this model and calculate the mode shapes, but with the calculation, it warns me that:

WARNING: The distance between the J marker and the I marker is 1.0000000003E-002.
(No warnings if less than +/-1.0E-003)
Fixed Joint = .hw5mw_ADAMS.TwrSec15ToTwrSecBelow_J
I Marker = .hw5mw_ADAMS.TowerSec15_P.TwrSec15ToTwrSecBelow_M
J Marker = .hw5mw_ADAMS.TowerSec14_P.TwrSec14ToTwrSecAbove_M
ERROR: Encountered error “No Library given and no default library for Sfosub” while processing user subroutine for hw5mw_ADAMS.Generator_SF
ERROR: Model did not pass verification phase.

So I want to know if there is something wrong with the ADAMS model or something else, my ADAMS edition is ADAMS2012.Firstly I want to upload the hw5mw_ADAMS.adm, but it says the board attachment quota has been reached. So I send it to you as an attachment in the last e-mail.
Best regards.

Dear Wenhua Wang,

I looked briefly at the hw5mw_ADAMS.adm file that you e-mailed me and don’t see any problems with it.

I’m not sure why are getting a “WARNING” about fixed joint TwrSec15ToTwrSecBelow_J because marker TwrSec15ToTwrSecBelow_M and marker TwrSec14ToTwrSecAbove_M both seem to be at the same position in space (0, 0, 61.32).

Regarding the “ERROR” you are getting, it dosn’t appear that your are using the user-created DLL based on the ADAMS-to-AeroDyn (A2AD), AeroDyn, and FAST source files. Have you already compiled this DLL using our provided CompileLinkA2AD.bat script?

Best regards,

Dear Prof Jonkman:
Than you very much for your reply and I have already compiled the CompilelinkA2AD.bat, but I have some questions. At first, I read the FAST USER GUIDE(P46), it told me that I should chang the following variables DF-loc, A2AD_LOC, AD_LOC and FAST_LOC. Then I opend the ‘CompilelinkA2AD.bat’, but I found that in the file the variables are NWTC_Lib_Loc, AeroDyn_Loc, Wind_Loc, FAST_Loc and A2AD_Loc. It is different from the USER GUIDE, and I only chang the variables in the file. At last I running the file in the command prompt, but it can not creat ADAMS.obj. So I want to know what’s wrong with the ‘CompilelinkA2AD.bat’ file?
Bset regards,

The CompilelinkA2AD.bat script has been modified significantly since the A2AD User’s Guide (2001) was written. We have documented some of the changes in the Addendum to the ADAMS2AD User’s Guide. You may find the instructions for compiling FAST from the command line helpful for understanding how the CompileLinkA2AD.bat script works (parts of it are very similar), and a search of this forum will provide some other assistance.

Please note that we cannot guarantee that Adams2012 will work with A2AD.