SYMPOSIA PAPER Published: 01 January 2002
STP10823S

On the Relation Between Engineering Load-Displacement Curves and True Stress Strain Behavior in Tests of Flat Tensile Specimens

Source

The effects of irradiation on true stress-strain constitutive laws associated with large increments of hardening, apparent yield drops, a significant loss of uniform strain and a propensity to microscopic flow localization as derived from the tensile test are evaluated. Analytical and finite element simulations of engineering stress strain curves for flat tensile specimens were performed with systematic variations in the true stressstrain laws. Coupled with large yield stress increases, relatively modest reductions in strain hardening can result in significant reductions in uniform strain. True strain softening eliminates uniform strains, produces apparent yield drops and greatly reduces the post-necking strains. Thus, constitutive laws with varying combinations of yield stress increases and reductions in strain hardening, or modest softening over a limited strain range, rationalize all the major observed engineering stress-strain trends following irradiation. Notably, the true flow stress is persistently increased following irradiation, even at high true strain. Continuum constitutive laws and J2 incremental flow plasticity theory appear to be adequate for modeling the deformation of irradiated materials. While source hardening or micro-localization mechanisms probably play some underlying role, they are neither a necessary nor sufficient condition for producing the behavior observed in tensile tests.

Author Information

Odette, GR
University of California, Santa Barbara, CA
He, MY
University of California, Santa Barbara, CA
Donahue, EG
University of California, Santa Barbara, CA
Lucas, GE
University of California, Santa Barbara, CA
Price: $25.00
Contact Sales
Related
Reprints and Permissions
Reprints and copyright permissions can be requested through the
Copyright Clearance Center
Details
Developed by Committee: E10
Pages: 221–233
DOI: 10.1520/STP10823S
ISBN-EB: 978-0-8031-5465-0
ISBN-13: 978-0-8031-2897-2