PPolySim OS
Structural & Geotechnical Pack · Multi-Solver

Pedestrian Bridge Vibration

Modes & comfort. This multi-solver chains 2 solvers into a single guided workflow — run each step in order and carry the result forward.

Workflow steps
  1. beam-deflection
  2. standing-waves
or unlock everything with Pro →
1

Beam Deflection

open full solver →
Beam Deflection & BendingLive

Controls

Presets

Euler-Bernoulli theory relates a beam's deflection and internal moment to its load, span, and flexural rigidity EI. Deflection grows with the cube or fourth power of span, which is why doubling a span is far worse than doubling the load. Educational tool — not a substitute for a stamped structural design.

▶ Run in Python

Data Inspector

Max deflection1.30 mm
Max moment12.5 kN·m
Span/deflectionL/3840

Governing equation

Reading this result: At L/3840 this beam clears the usual L/360 serviceability limit, so strength (not deflection) is likely to govern the design.

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

2

Standing Waves

open full solver →
Standing Waves on a StringLive

Controls

A string fixed at both ends can only vibrate at its harmonics. Each mode n has n+1 nodes (pink) that stay still while the antinodes swing — the physics of every stringed instrument.

Presets

▶ Run in Python

Data Inspector

Harmonicn = 3
Frequency330 Hz
Nodes4
Antinodes3
Wavelength2L/3

Governing equation

Reading this result: 3 half-wavelengths fit the string, so there are 3 antinodes (max swing) and 4 nodes (fixed points). At harmonic n = 3 the string sings at 330 Hz — exactly 3× the 110 Hz fundamental, and the wavelength is 2L/3.

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

Need a private, branded version?

We build custom solvers and workflows for labs, firms, agencies, and courses — your parameters, your branding, your data.

Explore Custom Solver Sets →

More in the Structural & Geotechnical pack

Frequently asked questions

What is the Pedestrian Bridge Vibration multi-solver?
Pedestrian Bridge Vibration is a guided workflow that chains 2 individual PolySim solvers into one end-to-end analysis, piping each result into the next step.
Is it free to use?
Yes. Every step runs entirely in your browser using real numerics — no install, no account, no cloud cost. Custom or private solver packs are available as a paid service.