engineering

Materials Fatigue & Failure Analysis

The science of structural fatigue — S-N curve modeling, crack propagation prediction, cumulative damage assessment via Miner's rule, stress concentration analysis, and Goodman diagram fatigue limit evaluation.

materials fatigueS-N curvecrack propagationMiner's rulestress concentrationGoodman diagramfatigue life

Materials fatigue is the progressive, localized structural damage that occurs when a material is subjected to cyclic loading. Unlike static failure, fatigue can cause catastrophic fracture at stress levels far below the material's yield strength — accounting for an estimated 90% of all metallic structural failures in service. Understanding fatigue mechanics has been critical since the railway axle failures of the 19th century.

These simulations let you construct S-N curves, predict crack growth rates using Paris' law, apply Miner's cumulative damage rule, analyze stress concentrations around geometric discontinuities, and evaluate safe operating regions with Goodman diagrams — essential tools for any structural or mechanical engineer.

5 interactive simulations

simulator

Fatigue Crack Propagation (Paris Law)

Simulate fatigue crack growth using the Paris-Erdogan law — predict how crack length evolves with loading cycles and estimate remaining component life

simulator

Goodman Diagram (Mean Stress Effect)

Construct modified Goodman diagrams — evaluate fatigue safety under combined alternating and mean stress for different materials and loading conditions

simulator

Miner's Rule (Cumulative Damage)

Apply Palmgren-Miner's linear damage accumulation rule — predict fatigue failure under variable amplitude loading with multiple stress levels

simulator

S-N Curve (Wohler Curve) Simulator

Generate and analyze S-N curves — plot stress amplitude versus cycles to failure for different materials and loading conditions

simulator

Stress Concentration Factor (Kt)

Analyze stress concentrations around geometric discontinuities — visualize how holes, notches, and fillets amplify local stress and reduce fatigue life