Automating tower geometry and sectional analysis

[giovanniboscu]

Hi everyone,

I'm sharing a small Python utility I've been developing called Continuous Section Field (CSF). It's currently in a beta stage (v0.9.1), and I've used the NREL 5-MW Reference Tower as a test case for geometry discretization.

The tool focuses on:

• Modeling non-prismatic members using ruled surfaces.
• Calculating sectional properties (A, I, Ip) along the tower height.
• Providing a simplified estimation of torsional rigidity ($J$).

I'm making the code available in case it's of interest to anyone working with tower geometry or needing a starting point for sectional analysis. Since it is a beta version, any feedback or suggestions on the approach would be greatly appreciated.

• Repository: giovanniboscu/continuous-section-field
• DOI: 10.5281/zenodo.18063426

Thanks!

[andrew-platt]

Thanks for your contribution to the community!

We should add a link to this in our documentation:

• Add link to CSF in documentation

[andrew-platt]

Link added to https://openfast.readthedocs.io/en/main/source/working.html#third-party-tools for release v5.0.0

[giovanniboscu]

Hi again,

I wanted to share an update since the first post in December.

The repository now includes a HISTWIN tower example a one-script workflow
where a single launcher generates the geometry, the action pipeline, and runs the
full analysis. No manual no programmig or editing of YAML files is required.

The example models the tower as a circular hollow tapered shell (H = 76.15 m,
base diameter 4.30 m, top diameter 3 m) under actions-examples/histwin,
and demonstrates a new 3D visualization feature: relative weight field coloring.

What the plot shows

Each polygon is colored by its own normalized material participation factor w(z) - a scalar field that scales the stiffness contribution:

• red → weight at full value (w ≈ 1.0, intact shell)
• blue → weight has dropped relative to its maximum

In this example the shell law introduces two localized Gaussian reductions
near the segment-joint elevations of the three-part tower (~21.8 m and ~48.4 m).
The two dips are directly visible as blue bands on the tower shell.

The law is a phenomenological equivalent field - it is not a direct fatigue model,
but represents the idea that the most sensitive regions of a segmented steel tower
are near the bolted flange connections between transported segments.

w(z) = max(0.84,
           1.0
           - 0.10 * exp(-((z - 0.286*L)^2) / (2*(0.03*L)^2))
           - 0.14 * exp(-((z - 0.636*L)^2) / (2*(0.03*L)^2)))

How to run it

Full instructions for both Linux/macOS and Windows (PowerShell) are included.

The repository also includes instructions for Linux/macOS and Windows (PowerShell), together with a complete CSF -> BModes -> ElastoDyn -> OpenFAST workflow example:

giovanniboscu/continuous-section-field - actions-examples/histwin

Quick start on Linux/macOS:

pip install csfpy

# clone only the histwin example
git clone --filter=blob:none --no-checkout https://github.com/giovanniboscu/continuous-section-field.git
cd continuous-section-field
git sparse-checkout init --cone
git sparse-checkout set actions-examples/histwin
git checkout main

cd actions-examples/histwin
chmod +x create_yaml-histwin.sh
./create_yaml-histwin.sh
./create_yaml-histwin.sh -action
csf-actions histwin_tower.yaml action.yaml

The out/ directory will contain the generated reports and plots.

Repository

• GitHub: https://github.com/giovanniboscu/continuous-section-field

Thanks again for adding CSF to the OpenFAST documentation.
Any feedback is welcome.