Dear Jason ,
Sorry, i would like ask about BModes_jj:
i tried first time without considering the foundation(hub_conn=1), and i have as a result for the natural frequency:
eigenvalue( 1) = 0.493762D+11 mode 1 frequency = 0.370346
When i consider the foundation i have as a resulat(hub_conn=3) :
eigenvalue( 1) = 0.436656D+05 mode 1 frequency = 0.000348
i would expect to find the natural frequency few percent lower than this value with the consideration of the interaction between foundation and the soil with the consideration of the rotation about horizontal axes wind turbine.
[b]====================== BModes v3.00 Main Input File ==================
NREL 5MW Tower
 General parameters 
true Echo Echo input file contents to *.echo file if true.
2 beam_type 1: blade, 2: tower ()
0. romg: rotor speed, automatically set to zero for tower modal analysis (rpm)

romg_mult: rotor speed muliplicative factor ()
87.6 radius: rotor tip radius measured along coned blade axis, OR tower height above ground level [onshore] or MSL offshore
0. hub_rad: hub radius measured along coned blade axis OR tower rigidbase height (m)
0. precone: builtin precone angle, automatically set to zero for a tower (deg)
0. bl_thp: blade pitch setting, automatically set to zero for a tower (deg)
3 hub_conn: hubtoblade or towerbase boundary condition [1: cantilevered; 2: freefree; 3: only axial and torsion constraints] ()
20 modepr: number of modes to be printed ()
t TabDelim (true: tabdelimited output tables; false: spacedelimited tables)
f mid_node_tw (true: output twist at midnode of elements; false: no midnode outputs)
 Bladetip or towertop mass properties 
3.500003109E+005 tip_mass bladetip or towertop mass (kg)
0.4137754432 cm_loc tipmass c.m. offset from the tower axis measured along xtower axis (m)
1.9669893542 cm_axial tipmass c.m. offset tower tip measures axially along the z axis (m)
4.370E7 ixx_tip blade lag mass moment of inertia about the tipsection x reference axis (kgm^2)
2.353E7 iyy_tip blade flap mass moment of inertia about the tipsection y reference axis (kgm^2)
2.542E7 izz_tip torsion mass moment of inertia about the tipsection z reference axis (kgm^2)
0. ixy_tip cross product of inertia about x and y reference axes(kgm^2)
1.169E6 izx_tip cross product of inertia about z and x reference axes(kgm^2)
0. iyz_tip cross product of inertia about y and z reference axes(kgm^2)
 Distributedproperty identifiers 
1 id_mat: material_type [1: isotropic; nonisotropic composites option not yet available]
‘CS_monopile_tower_secs.dat’ : sec_props_file name of beam section properties file ()
Property scaling factors…
1.0 sec_mass_mult: mass density multiplier ()
1.0 flp_iner_mult: blade flap or tower fa inertia multiplier ()
1.0 lag_iner_mult: blade lag or tower ss inertia multiplier ()
1.0 flp_stff_mult: blade flap or tower fa bending stiffness multiplier ()
1.0 edge_stff_mult: blade lag or tower ss bending stiffness multiplier ()
1.0 tor_stff_mult: torsion stiffness multiplier ()
1.0 axial_stff_mult: axial stiffness multiplier ()
1.0 cg_offst_mult: cg offset multiplier ()
1.0 sc_offst_mult: shear center multiplier ()
1.0 tc_offst_mult: tension center multiplier ()
 Finite element discretization 
61 nselt: no of blade or tower elements ()
Distance of element boundary nodes from blade or flexibletower root (normalized wrt blade or tower length), el_loc()
0 0.003481894 0.010445682 0.017409471 0.024373259 0.031337047 0.038300836 0.045264624 0.052228412 0.059192201 0.066155989 0.073119777 0.080083565 0.087047354 0.094011142 0.10097493 0.107938719 0.114902507 0.121866295 0.128830084 0.135793872 0.13990 0.149721448 0.156685237 0.163649025 0.170612813 0.177576602 0.18454039 0.191504178 0.198467967 0.205431755 0.212395543 0.219359331 0.22632312 0.233286908 0.240250696 0.247214485 0.250696379 0.320334262 0.37971 0.424791072 0.45961 0.486635 0.51366 0.54068 0.5677 0.594715 0.62173 0.64875 0.67577 0.70279 0.72981 0.75683 0.78385 0.81087 0.83789 0.864905 0.89192 0.91894 0.94596 0.97298 1.0
 Properties of tower support subsystem (read only if beam_type is 2) 
0 tow_support: : aditional tower support [0: no additional support; 1: floatingplatform or monopile with or without tension wires] ()
0.0 draft : depth of tower base from the ground or the MSL (mean sea level) (m)
0.0 cm_pform : distance of platform c.m. below the MSL (m)
0 mass_pform : platform mass (kg)
Platform mass inertia 3X3 matrix (i_matrix_pform):
0. 0. 0.
0. 0. 0.
0. 0. 0.
0.0 ref_msl : distance of platform reference point below the MSL (m)
Platformreferencepointreferred hydrodynamic 6X6 matrix (hydro_M):
0. 0. 0. 0. 0. 0.
0. 0. 0. 0. 0. 0.
0. 0. 0. 0. 0. 0.
0. 0. 0. 5.650000E+7 0. 0.
0. 0. 0. 0. 5.650000E+07 0.
0. 0. 0. 0. 0. 0.
Platformreferencepointreferred hydrodynamic 6X6 stiffness matrix (hydro_K):
0. 0. 0. 0. 0. 0.
0. 0. 0. 0. 0. 0.
0. 0. 0. 0. 0. 0.
0. 0. 0. 4.356000E+10 0. 0.
0. 0. 0. 0. 4.356000E+10 0.
0. 0. 0. 0. 0. 0.
Mooringsystem 6X6 stiffness matrix (mooring_K):
0. 0. 0. 0. 0. 0.
0. 0. 0. 0. 0. 0.
0. 0. 0. 0. 0. 0.
0. 0. 0. 0. 0. 0.
0. 0. 0. 0. 0. 0.
0. 0. 0. 0. 0. 0.
Distributed (hydrodynamic) addedmass per unit length along a flexible portion of the tower length:
0 n_secs_m_distr: number of sections at which added mass per unit length is specified ()
0. 0. : z_distr_m [row array of size n_added_m_pts; section locations wrt the flexible tower base over which distributed mass is specified] (m)
0. 0. : distr_m [row array of size n_added_m_pts; added distributed masses per unit length] (kg/m)
Distributed elastic stiffness per unit length along a flexible portion of the tower length:
0 n_secs_k_distr: number of points at which distributed stiffness per unit length is specified ()
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 : z_distr_k [row array of size n_added_m_pts; section locations wrt the flexible tower base over which distributed stiffness is specified] (m)
595318000.0 1165208000 1129400000 1095553000 1059931000 1024493000 989209000 953643000 918718000 883287000 847803000 812541000 777187000 741870000 706616000 671440000 636229000 600957000 565919000 530470000 495081000 459574000 385327000 305479000 280059000 254125000 227500000 200112000 171927000 143115000 114173000 80184000 52237000 35561000 20912000 9000000 1156000 : distr_k [row array of size n_added_m_pts; distributed stiffness per unit length] (N/m^2)
Tension wires data
0 n_attachments: no of wireattachment locations on tower [0: no tension wires] ()
3 3 n_wires: no of wires attached at each location (must be 3 or higher) ()
6 9 node_attach: node numbers of attacments location (node number must be more than 1 and less than nselt+2) ()
0.e0 0.e0 wire_stfness: wire spring constant in each set (see users’ manual) (N/m)
0. 0. th_wire: angle of tension wires (wrt the horizontal ground plane) at each attachment point (deg)
END of Main Input File Data *********************************************************************
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Best regards