Variation in Plastic Strain Range of a Rolled Steel for General Structures SS400 during Fatigue Process. (Based on Logistic Analyses).

Abstract

The plastic strain range of stress-strain curve during fatigue process was measured for an annealed and a rolled steel for general structure SS400. It was found that variation in plastic strain range Δερ was expressed using movable dislocation density ρ and Burgers vector b. The movable dislocation density was estimated from the plastic strain range and was expressed as a function of the number of stress cycles n by the following equations using a model based on the multiplication and annihilation process of dislocations. Δερ= √ρb, ρ= 1/(β/α+ 1/ρ0e-an+βk/αn). It was concluded that the calculation using this equation corresponds well with plastic strain range.