Approximation of stress‐strain curves by various functions

Abstract

Stress-strain curves obtained by measurements based on four different strain-rates relating to steels St 37-3 and X 10 CrAI18 were approximated by various functions. The mathematical procedure used herein is of advantage inasmuch as no distortion through transformation of the approximating function occurs. The transition from the area of spread of Luders tines to homogeneous deformation, which occurs in steel St 37-3, is discussed.Beschreibung von Spannungs-Dehnungs-Kurven durch verschiedene Funktionen. Die bei vier verschiedenen Dehngeschwindigkeiten gem essen en Spannungs-Dehnungs-Kurven der Stahle St 37-3 und X 10 CrAI18 wurden durch verschiedene Funktionen anqenahert. Das hierbei verwendete Naherunqsvertahren hat den Vorteil, daB keine Verzerrung der anqenaherten Funktion durch eine Transformation auftritt. Der Obergang vom Bereich der Liidersbandausbreitung zur homogenen Verformung wird am Beispiel des Stahls St 37-3 diskutiert.

Perceptive Review of Ferrous Micro/Macro Material Models for Thermo-Mechanical Processing Applications

“…For reasonably monotonous conditions of deformation algebraic equations describing flow stress as function of strain, strain rate, and temperature are commonly used in simulations of metal forming processes. Various functions that have been used in practical applications can be found in various papers . Among a number of approaches, the following three should be particularly distinguished.…”