PPolySim OS

FEA Truss Simulator

Load a truss and watch it deform. Members turn blue in tension and pink in compression, scaled by how hard they're working.

FEA — 2D Truss StudioLive

Controls

A finite-element truss under a tip load. Members are colored by axial force; the shape shows the (scaled) deformation.

Presets

▶ Run in Python

Data Inspector

Nodes7
Members11
Solvesingular
Max displacement0.000
Max axial force0.0

Governing equation

Reading this result: A 20-unit tip load drives a peak member force of 0.0. Linear FEA is linear: double the load and both the deflection and every member force double exactly. The 20x slider only magnifies the true (tiny) displacement so you can see it.

Runs locally in your browser — free forever. Scale to the cloud when reality gets heavy.

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How it works

This is the direct-stiffness method used in real structural FEA. Each bar contributes a stiffness matrix in global coordinates; PolySim assembles the global system, applies your supports and loads, and solves the linear system for nodal displacements — then back-computes axial force in every member. The displayed shape is the true (scaled) deformed geometry.

Ask the AI about this model

The math, the assumptions, real-world uses, or a code translation — explained for this exact simulation.

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Frequently asked questions

Is this finite element analysis tool really free?
Yes. FEA Truss Simulator runs entirely in your browser using your device's own compute, so local use is free forever. You only pay Compute Tokens if you scale a job to the cloud.
Do I need to install anything?
No. Everything runs client-side in a modern browser — no downloads, no license, no account required to start.
Can I save or share my simulation?
Create a free account to save projects, and use a shareable embed or minted DOI to publish a live, interactive version anywhere.
How accurate are the results?
The solver uses established numerical methods, but results are for research and educational purposes and should be validated against experiment or professional review before you rely on them.