What is the Fatigue Life Predictor multi-solver?

Fatigue Life Predictor is a guided workflow that chains 2 individual PolySim solvers into one end-to-end analysis, piping each result into the next step.

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.

Chemistry & Materials Pack · Multi-Solver

Fatigue Life Predictor

S-N to life. This multi-solver chains 2 solvers into a single guided workflow — run each step in order and carry the result forward.

Workflow steps

fatigue
→stress-strain

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Fatigue

open full solver →

Fatigue (S-N Curve)Live

failure under cyclic load

Controls

Presets

Ultimate strength (MPa)

Stress amplitude (MPa)

Ferrous (has endurance limit)

Repeated loading well below the ultimate strength can still break a part — metal fatigue. The S-N curve plots stress amplitude against cycles to failure. Steels have an endurance limit: below it they last essentially forever, but aluminum has none and eventually fails at any stress. Cause of many catastrophic aircraft and bridge failures.

▶ Run in Python

Data Inspector

Endurance limit250 MPa

Cycles to failure1.17e+5

Verdictfinite life

Governing equation

N = (\frac{σ _{a}}{σ _{f}^{'}})^{1/ b}, σ_{a} = 300 MPa \Rightarrow N = 1.17 e + 5 cycles

Reading this result: At 300 MPa the part fails after about 1.2e+5 cycles. Drop below the 250 MPa endurance limit to reach infinite life.

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

↓

Stress Strain

open full solver →

Stress-Strain CurveLive

tensile testing

Controls

Presets

Applied strain

Pull on a material and its stress-strain curve tells its story: a straight elastic region with slope equal to Young's modulus, a yield point where permanent deformation begins, a peak at the ultimate tensile strength, and finally fracture. Ductile metals stretch far; brittle ones like cast iron snap with almost no warning.

▶ Run in Python

Data Inspector

Young's modulus200 GPa

Current stress294 MPa

UTS400 MPa

Regionplastic

Governing equation

σ = E ε, E = 200 GPa, ε = 0.050, σ \approx 294 MPa

Reading this result: Past yield (250 MPa): Mild steel is deforming permanently and hardening toward its 400 MPa ultimate strength.

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

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Frequently asked questions

What is the Fatigue Life Predictor multi-solver?: Fatigue Life Predictor 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.