Comparative Analysis by the Newton Method of New Constitutive Strain Dependent Creep Equations Based on the Garofalo Equation

Abstract:

The improvement of optimization numerical methods for constitutive equations has been the first aim of this research. A subordinate optimization algorithm, based on Newton method, through “ad hoc” assessment, has been developed. Application to hot torsion data of AISI4145 with two grain sizes has been carried out. It is concluded that the Newton method is an excellent algorithm for the optimization of strain dependent constitutive equations. Two models are presented as alternative to the generalized Garofalo model: the normalized stress exponent model (NSE) and the Generalized Sherby model (SG). The NSE model is the most precise to restitute the experimental stress-strain curves.

• Periodical: Materials Science Forum (Volumes 783-786)
• Pages: 2136-2141
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.783-786.2136
• Online since: May 2014
• Authors: Manuel Carsí*, Victor Gutiérrez, Ignacio Rieiro, Esther Benavente, Oscar A. Ruano
• Keywords: Constitutive Equations, Creep Equations, Optimization Method

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