I have a few questions about the input and usage of BModes (used for a tower):
what is the relationship between the two following inputs?
el_loc(i) - found in the main input file
sec_loc - found in the section properties file
Both are adimensional, running from 0 (bottom) to 1 (top). What is the “right” usage of them? In the supplied input sample, they are similar but not identical:
0. 0.08 0.16 0.24 0.32 0.40 0.48 0.56 0.64 0.72 0.80 0.90 1.0
0 0.1111 0.2222 .... 0.888 1
(equal steps, 0.1111)
The tower I am modelling is slightly conical, I have identified about 15 significative sections, including flanges, irregularly distributed along Z. Should I try to follow with el_loc the same distribution? By the way, is it correct to try to simulate the flanges with short, thick segments of tower? I used to do this with standard FEM codes (e.g. ANSYS) in order to correctly account for the concentrated mass and the locally increased stiffness.
the tower ends at a given height Ztop above the ground. The center of mass of the nacelle+rotor is at Zcg, higher than Ztop. In the figure 6 pag. 18 of the user manual, it seems that the tower must end at Zcg. Is this correct? if yes, I plan to insert a dummy tower segment, very stiff and very light, to “reach” the right Zcg. Is this a good idea?
I have tried to recompile the code, in order to use a different number of segments than 12. I am using a freeware Fortran compiler called G95 (http://g95.sourceforge.net/). I get a compilation error when the first USE statement is found (line 365: USE Struc). The compiler is looking for a file called “Struc.mod”. Maybe I am doing something wrong…
as usual, thanks a lot for your advice