Bridge load

One load. Three bridges. Which fails first?

Stack weight on a beam, a truss, and a suspension span. Watch them droop, cables pull taut — then crank it until one snaps.

Load

10 t

span 30 m

Deflection

— mm

mid-span droop

Max stress

— MPa

vs — limit

Bridge design

Load10 tonnes

Span length30 m

Stress vs limit — who fails first

How to use

Pick a bridge design — beam, truss, or suspension. Drag load and span, or hit Crank the weight to ramp the load automatically. The canvas shows the deck deflecting and cables tensioning live; the bars below race all three designs' stress toward their failure limit. The first bar to fill is the first design to break.

Beam vs Truss vs Suspension

Beam: simple, cheap. Bending stress σ = Mc/I. Fails fast on long spans (>40 m gets impractical).

Truss: triangulated; members in pure tension/compression. Efficient to ~150 m.

Suspension: cables carry tension only. Spans > 1 km feasible (Akashi-Kaikyō: 1,991 m).

Why each fails differently

Beam fails by yielding the bottom fiber. Truss fails by buckling of a compression member (Euler). Suspension cable fails by yield of steel wire — but more likely the tower buckles first.

Citations

Gere, J.M. & Goodno, B.J. (2017). Mechanics of Materials (9th ed.). Cengage Learning. Beam-bending stress σ = Mc/I and column-buckling derivations.
Euler, L. (1744). Methodus inveniendi lineas curvas maximi minimive proprietate gaudentes. Original derivation of the buckling load P_cr = π²EI/L².
Timoshenko, S.P. & Gere, J.M. (1961). Theory of Elastic Stability (2nd ed.). McGraw-Hill.
Gimsing, N.J. & Georgakis, C.T. (2012). Cable Supported Bridges: Concept and Design (3rd ed.). Wiley. Suspension-cable tension T = wL/(8s) and tower-stress analysis.

Built by Joshua Chua · Fable rebuild · vanilla JS + Canvas