Quadratic (Elliptic) Method Fatigue Curve Equationn

Strength and Mechanics of Materials

Quadratic ( Elliptic ) Method 

Quadratic ( Elliptic ) Method  Formula

Where:
Amplitude of normal (shear) stress = Amplitude of normal (shear) stress [MPa,psi]
Endurance limit at constant strength = Endurance limit at constant strength [MPa,psi]
Mean cycle stress = Mean cycle stress [MPa,psi]]
Virtual mean stress = Virtual mean stress [MPa,psi]
Ultimate tensile strength = Ultimate tensile strength [MPa,psi]
Ultimate tensile strength equivalence = When SUS  SU