Frame3DD — The Complete Guide: A Free Input-File 3D Frame Solver Built for Automation
Frame3DD is an open-source (GPL) solver for space frames and trusses, written by Henri Gavin of Duke University. It has no drawing interface: you write an input file with nodes, elements, sections, supports and loads, and get a results file back.
Frame3DD
Frame3DD Project
3D frame and truss solver driven by an input file — excellent for automation and repeat runs.
Get it from the vendorWhat you get
- Static analysis — displacements, reactions and internal forces in every element.
- Geometric stiffness — the option to include second-order effects in the analysis.
- Modal analysis — natural frequencies, mode shapes and participation factors.
- Matrix condensation — static, Guyan and dynamic condensation to reduce the model.
- Plots — output ready for displaying the deformed structure with gnuplot.
Where it is strong
When you need to run the same frame tens or hundreds of times — a parametric study, optimisation or a sensitivity check — generate the input files from Python or a spreadsheet, run them in batch and collect the results. For everyday design with drawings and on-screen display, it is not the right tool.
Related tools
For 2D frames with a graphical interface — Ftool. For advanced nonlinear and dynamic analysis, also scripted — OpenSees. For general finite element analysis — CalculiX.
Ftool
PUC-Rio, Tecgraf
2D frame and beam analysis — fast to enter, aimed at learning and order-of-magnitude checks.
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OpenSees
Pacific Earthquake Engineering Research Center, UC Berkeley
Nonlinear and dynamic structural analysis driven by scripts, from the earthquake engineering world.
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Python
Python Software Foundation
The language behind most modern engineering computation, and its full ecosystem.
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CalculiX
CalculiX Project
Open-source FEA with syntax close to Abaqus. The solver behind the FreeCAD FEM workbench.
Get it from the vendorThe bottom line
Frame3DD is a small, fast, well-documented frame analysis engine that suits anyone who thinks in terms of automation.