Hall of Structure · Catalogue 11

🏗️ The Stress Gallery

Apply loads to a beam and watch stress propagate in real time. See shear force and bending moment diagrams update live. The colour map shows where failure begins — red zones are where your shelf, joist, or lintel will crack first.

Exhibit A · The living beam

Load a beam and watch it flex

Load position along beam 50%

Load force (kN) 5 kN

Beam length (m) 3.0 m

Beam depth (mm) 200 mm

What you're seeing. The top beam shows the deflection curve — how much it bends. The middle diagram is shear force (V) — the internal cutting force. The bottom diagram is bending moment (M) — the internal twisting force. The stress colour map on the beam shows where tension (bottom, blue) and compression (top, red) are greatest. When stress exceeds the material's strength, the beam fails.

Exhibit B · Why beams are tall, not wide

The moment of inertia secret

A beam's resistance to bending depends on its moment of inertia (I = bd³/12). Notice the d³ — depth is cubed. Double the depth and you get 8× stronger. This is why I-beams are tall and thin, why floor joists are placed on edge, and why a ruler bends easily flat but is stiff on its side. The shape on the right is equally strong as the one on the left but uses far less material.