Table of Contents
ISRN Civil Engineering
Volume 2011, Article ID 656401, 11 pages
http://dx.doi.org/10.5402/2011/656401
Research Article

True Stress-True Strain Models for Structural Steel Elements

1AMEC Earth and Environmental, Edmonton, AB, Canada T6B 3P6
2Department of Civil Engineering, McMaster University, 1280 Main Street West, Hamilton, ON, Canada L8S 4L7

Received 19 April 2011; Accepted 30 May 2011

Academic Editor: D. Li

Copyright © 2011 P. Arasaratnam et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

A standard uniaxial tensile test, which establishes the engineering stress-strain relationship, in general, provides the basic mechanical properties of steel required by a structural designer. Modern numerical analysis techniques used for analysis of large strain problems such as failure analysis of steel structures and elements metal forming, metal cutting, and so forth, will require implementation and use of true stress-true strain material characterization. This paper establishes a five stage true stress-strain model for A992 and 350W steel grades, which can capture the behavior of structural steel, including the postultimate behavior of steel, until fracture. The proposed model uses a power law in strain hardening range and a weighted power law in the postultimate range. The true stress-true strain model parameters were established through matching of numerical analysis results with the corresponding standard uniaxial tensile test experimental results. The material constitutive relationship so derived was then applied to predict the load-deformation behavior of coupons with a hole in the middle region subjected to direct tension loading. The predicted load-deformation behavior of perforated tension coupons agreed well with the corresponding test results validating the proposed characterization of the true stress-true strain relationship for structural steel.