Quickstart: your first model in the browser

Fastest route: open an example

The quickest way to get a feel for FERS is to solve something that already works. From the home page, pick Simple Shed or Solar Rail and press Calculate. You get displacements, axial/shear/moment diagrams and reactions on a model that is known to be correct, so you can learn the interface without also debugging your own geometry.

The examples library has more, including a portal frame and a full EN 1993-1-1 steel member check with a per-clause hand-calculation trace.

Prefer to start from a form rather than a 3D model? The free 2D frame calculator and the beam calculators solve with the same engine and need nothing set up at all.

Build your own model

Work through the Data Workspace tabs in this order. Each step depends on the one before it, which is why the tabs are arranged this way.

1. Materials — E-modulus, density and yield stress — for example S235 steel. Everything downstream references a material, so this comes first.
2. Sections — Cross-section properties (area, i_y, i_z, j), each referencing a material. Bending about the strong axis uses i_z — see conventions and units before you type a second moment of area.
3. Nodes — The X, Y, Z coordinates of your structure's joints. Y is up.
4. Nodal supports — Boundary conditions. A pinned support fixes Ux/Uy/Uz and leaves rotations free; assign the support to a node from the Nodes tab once you have defined it.
5. Members — Connect two nodes with a section. A member is a 2-node beam element with six degrees of freedom per node.
6. Load cases and loads — Create a load case (for example "Permanent"), then add nodal, distributed or surface loads to it. Directions are global X/Y/Z, so (0, -1, 0) is straight down.
7. Calculate — Run the analysis from the top bar. Results appear in the Results tabs and in the viewport.

The welcome tour walks through the same interface interactively — replay it any time from Help (?) → Show welcome tour.

Read the results

After a solve, the Results tabs carry nodal displacements, member internal forces, reactions and — if you added them — unity checks. The viewport draws the deflected shape and the diagram you select.

Diagrams are exact rather than interpolated: member displacements are sampled from the solved element, so a fixed-fixed beam under a uniformly distributed load reports the true wL⁴/384EI sag rather than a straight-line approximation between end values.

Before trusting a large model, solve a single-span case whose closed-form answer you know and compare. The accuracy benchmarks and the NAFEMS benchmark set do exactly this, in the browser, with the target-versus-FERS error shown for each.

Save and export

Your model can be exported as JSON from the Download menu at any point — that file is the same format the Python package and the REST API consume, so a model started in the browser can be finished in a script.

Saved cloud storage is part of the Pro plan; on the free tier you keep models as local JSON. The free tier solves models up to 100 members, Pro up to 10,000.

Where to go next

• Install the Python package to drive the same solver from a script.
• Use it from JavaScript — the solver is published as a WebAssembly npm package that runs in the browser with no server round-trip.
• Call the REST API from any language, or import the OpenAPI spec into a client generator.
• Connect an AI agent — Claude, ChatGPT, Cursor and VS Code can drive FERS over MCP.
• Keyboard shortcuts for the modelling tools once you are past the first model.