[BUG] Issue 97 no attribute 'sec_props' in from_windio_with_monopile

[TheMercer]

pyBmodes version

1.5.0

Python version

3.11

How did you install pyBmodes?

pip install pybmodes (from PyPI)

Operating system

Windows 11

What happened?

tower._bmi.support.sec_props.flp_stff[-1] doesnt exist

AttributeError: 'NoneType' object has no attribute 'sec_props'

What did you expect?

The data to be there so it can be used

Minimal reproducer

tower = Tower.from_windio_with_monopile(Turbine_yaml, tip_mass = rna_mass, n_nodes = 50)         # or Tower.from_bmi("my_tower.bmi")
foundation = MudlineFoundation.from_soil_properties(
    pile_diameter=10.0, pile_length_embedded=45.0,
    pile_EI=tower._bmi.support.sec_props.flp_stff[-1],  # or pass directly
    soil_E=140e6, soil_nu=0.4,
    soil_profile="homogeneous", pile_behaviour="auto",
)
tower._bmi.support.mooring_K = foundation.as_mooring_K()
tower._bmi.hub_conn = 3

Traceback or unexpected output

Anything else?

No response

[SMI-Lab-Inha]

Fixed in 1.15.1 (released today, Release notes) via #119, auto-closed by the merge.

You were right that the snippet in my #97 close comment was broken on two counts. from_windio_with_monopile builds a clamped-base cantilever with hub_conn = 1 and does not populate bmi.support (it stays None), and the section properties live at tower._sp rather than tower._bmi.support.sec_props. Apologies for the wasted time.

1.15.1 ships a public one-call wiring so you no longer have to touch private BMI fields:

import math
from pybmodes import MudlineFoundation
from pybmodes.models import Tower

tower = Tower.from_windio_with_monopile(Turbine_yaml, tip_mass=rna_mass, n_nodes=50)

# Compute the foundation from soil and pile properties. pile_EI comes
# from the monopile geometry you already know (or read out of the WindIO
# ontology); no need to fish through tower internals.
D_P = 10.0
t_P = 0.10
pile_EI = 210e9 * math.pi / 64.0 * (D_P**4 - (D_P - 2.0 * t_P) ** 4)

foundation = MudlineFoundation.from_soil_properties(
    pile_diameter=D_P, pile_length_embedded=45.0, pile_EI=pile_EI,
    soil_E=140e6, soil_nu=0.4,
    soil_profile="homogeneous", pile_behaviour="auto",
)

modal = tower.attach_mudline_foundation(foundation).run(n_modes=4)

attach_mudline_foundation switches the BMI to hub_conn = 3 (soft monopile), drops in a PlatformSupport with the foundation's coupled mudline springs in mooring_K, and returns self for chaining. Refuses cleanly on a free-base floating model (hub_conn = 2) or pinned-free cable (hub_conn = 4).

pip install --upgrade pybmodes==1.15.1 to pick it up.

The distributed Winkler half of #118 (per-station soil rate via distr_k rather than a lumped mudline contribution) stays open as a separate scope. I will revisit it as a 1.16 minor release.