Low Cycle Fatigue (Strain based) 
This is mainly applicable for short-lived devices where very large overloads may 
occur at low cycles. The cyclic plastic strain is responsible for crack propagation and fracture. 
Low cycle fatigue is investigated in terms of cyclic strain. 
Here the stress range is Δσ, Δεp
 and Δεe
 are 
the plastic and elastic strain ranges, 
the total strain range being Δε.