eFatigue, a trusted source for fatigue analysis

Fatigue Calculator

The eFatigue website includes Fatigue Calculators and Fatigue Analyzers. There are no charges or accounts required to use any Fatigue Calculator. An eFatigue subscription will give you access to the more computationally intensive Fatigue Analyzers as well as enhanced features for Fatigue Calculators, including the ability to save data and results on our server.

Fatigue failures are always a consideration for any structure that is dynamically or cyclically loaded. The effective use of the appropriate fatigue technology and analysis is an essential part of assuring the fatigue resistance and durability of all mechanical components. In an era of efficient light weight design, fatigue considerations take on added importance.

Most fatigue technologies and fatigue analysis software have only been used by experts with costs to match. No longer. Designed and supported by the fatigue group at the University of Illinois, the Fatigue Calculator portion of the eFatigue website contains technologies and tools needed for accurate fatigue assessments with an interface that is easy for the non-expert to navigate.

With a Fatigue Calculator you can quickly:

  • do a simple fatigue analysis,
  • compare results from different methods,
  • find a stress concentration factor, or
  • find material properties

Each Fatigue Calculator includes a "Learn by Example" button that will walk you through its input parameters and methods. Databases for material properties, stress concentration factors, and stress intensity factors are included. With a Fatigue Calculator, any engineer can quickly and easily conduct a fatigue or durability analysis.

Fatigue analysis methods are based on stress-life, strain-life or crack growth:

This method is often called the SN approach and is appropriate for long life situations where the strength of the material and the nominal stress control the fatigue life. Stresses remain elastic even around stress concentrations.

This method sometimes referred to as the εN approach and is used for finite fatigue lives in ductile materials where plasticity around stress concentrations is important.

Crack Growth
Fracture mechanics, LEFM, is used to determine how long it will take a crack to grow to a critical size.