EngiRef / Materials Engineering Formula

Basquin Equation (Fatigue)

Basquin Equation (Fatigue): High-cycle fatigue life prediction. A Fatigue formula in materials engineering. Variables σₐ, σ'f, Nf and b, each with SI and…

Fatigue

Specification

Name
Basquin Equation (Fatigue)
Discipline
materials
Category
Fatigue
LaTeX
\sigma_a = \sigma_f^\prime (2N_f)^b
Description
High-cycle fatigue life prediction
Conditions
Empirical stress-life relation; 2Nf is reversals to failure
Can solve for
σₐ, Nf
Tags
fatigue, basquin, cycles, life

Variables

Variables for Basquin Equation (Fatigue)
SymbolNameUnitSi UnitImperial Unit
σₐStress AmplitudePaPapsi
σ'fFatigue Strength CoefficientPaPapsi
NfCycles to Failure - - -
bFatigue Strength Exponent - - -

Common questions

What is the Basquin Equation (Fatigue) formula?
High-cycle fatigue life prediction. It sits under Fatigue, Materials engineering in the EngiRef reference.
What do the symbols in the Basquin Equation (Fatigue) formula mean?
In Basquin Equation (Fatigue), σₐ is stress amplitude in Pa; σ'f is fatigue strength coefficient in Pa; Nf is cycles to failure; b is fatigue strength exponent.
When does the Basquin Equation (Fatigue) formula apply?
Basquin Equation (Fatigue) holds under this condition: Empirical stress-life relation; 2Nf is reversals to failure.