Quick start

In about ten minutes you will model a simply supported steel beam under a uniform load, read the reactions, shear force and bending moment, and confirm them against the textbook formulas.

Follow along

Open run.edubeam.app in a second tab. If a model is already loaded, use Clear mesh (trash icon in the app bar) to start empty—tick Delete materials and Delete cross sections to start completely fresh.

The problem

A 6 m simply supported beam (pinned at the left, roller at the right) carries a uniform load of 12 kN/m. Material: steel, $E = 210\ \text{GPa}$, $G = 81\ \text{GPa}$. Section: an IPE 200, $A = 28.5\ \text{cm}^2$, $I_y = 1943\ \text{cm}^4$, $h = 200\ \text{mm}$.

1. Check the units

Look at the units chip in the bottom-right corner of the viewer (e.g. m · m² · kN · kNm · MPa). These are the units every input field and result uses. The defaults are metres, kN, kNm and MPa, which is what this tutorial assumes. To change them, click the chip or open Settings → Language & Locale.

2. Add the material and cross section

Elements need a material and a cross section before they can exist, so create them first.

1. Open the Materials tab in the bottom bar and click Add material.
2. Enter E = 210000 MPa, G = 81000 MPa, leave density and α = 0.000012 1/K. Click Add material. (Or click Material library and pick Steel (S235)—it has exactly these values.)
3. Open the Cross sections tab and click Add cross section.
4. Enter Area = 0.00285 m², Iy = 1.943e-5 m⁴, Height = 0.2 m, Shear coefficient = 1. Click Add cross section.

Why does the shear coefficient matter?

EduBeam uses Timoshenko beam elements, which include shear deformation. k is the shear correction factor ($k \approx 0.83$ for a rectangle, $\approx 0.4$–$0.5$ for the web of an I-section when $A$ is the full area). Setting k = 1 with the full area slightly understates shear flexibility; for a slender beam like this one the difference in deflection is well under 1 %. See the beam theory page for the formula.

3. Add the nodes

1. Open the Nodes tab and click Add node. Enter X = 0, Z = 0 and confirm. The node is labelled 1.
2. Click Add node again with X = 6, Z = 0. This is node 2.

You can also place nodes with the mouse: choose Add using mouse (or right-click the canvas → Add node while holding Ctrl) and click on the grid. With Snap to grid on (S), clicks land on 0.1 m increments.

4. Connect them with an element

1. Open the Elements tab and click Add element.
2. Choose Initial node 1, End node 2. The material and cross section you created are pre-selected. Confirm.

A black line appears between the nodes. Press F to fit it to the screen.

5. Add the supports

In the Nodes tab, the Supported DOFs column has three checkboxes per node: Dx, Dz, Ry.

• Node 1: tick Dx and Dz → a pinned support symbol appears.
• Node 2: tick Dz only → a roller.

The same checkboxes are available by clicking a node in the viewer and choosing Node supports. See Nodes & supports for every support type.

6. Add the load

1. Open the Loads tab and click Add element load.
2. Load type: Uniformly distributed load. Element: 1.
3. Enter fz = 12 kN/m and leave fx = 0. Confirm.

Positive fz points in the +z direction, which is downward on screen—so a positive value is a gravity-type load. See conventions.

7. Read the results

The solution appears the instant the load is added. Open the viewer settings panel (gear button, top-right of the viewer) to switch overlays on and off:

Overlay	What you should see
Reactions	Two upward arrows of 36 kN at nodes 1 and 2.
Vz (x)	A straight line from +36 kN at the left to −36 kN at the right, crossing zero at mid-span.
My (x)	A parabola with its extreme 54 kNm at mid-span.
Deformed shape	A symmetric sag. Hover node 1 to read its rotation: about 0.0265 rad.

The Results tab in the bottom bar gives the numbers: Nodal results lists Dx, Dz, Ry for each node, Element results lists the end forces of each element in its local coordinate system.

If the diagrams look too large or too small, drag the Results scale slider in Settings → Viewer settings → Sizes.

8. Check by hand

Quantity	Formula	Hand value	EduBeam
Reaction	$R = qL/2$	36 kN	36 kN
Max shear	$V = qL/2$	36 kN	36 kN
Max moment	$M = qL^2/8$	54 kNm	54 kNm
End rotation	$\varphi = qL^3/(24EI)$	0.02647 rad	0.02647 rad
Mid-span deflection	$w = 5qL^4/(384EI)$	49.6 mm	49.6 mm

Everything matches. More hand-check recipes (cantilever, fixed beam, truss) are in Checking results by hand.

9. Experiment

This is where EduBeam earns its keep. Try each of these and watch the diagrams update:

• Drag node 2 to the right: the moment grows with $L^2$.
• Tick Ry at node 1 to make it fixed: the mid-span moment drops, a hogging moment appears at the support.
• Add a third node at X = 3 by clicking on the beam with Add using mouse—choose Connect to structure so the beam is split—and then tick its Dz to make a two-span continuous beam.
• Tick an End hinge on an element in the Elements tab to release the moment at one end.
• Press Ctrl+Z to undo any step.

10. Save or share

• Share model (app bar) gives you a URL that contains the whole model—paste it into an e-mail, a chat or slides.
• Save project (menu ☰, or Ctrl+S) downloads a project.json you can re-open later with Open project or by dropping it onto the app.

Your model is also kept in the browser's local storage, so a page reload does not lose it. See Import, export & sharing.

Where next

• Examples — open ready-made frames and trusses in one click.
• Loads — trapezoidal, concentrated and temperature loads, prescribed displacements.
• Keyboard & mouse — work faster on the canvas.