Several investigators have reported an acceleration of creep in metals due to repeated stress reversals. In order to determine the temperature dependence of this acceleration, reversed creep experiments have been carried out on commercially pure aluminum at temperatures from 300 to 510 K and shear stresses between ±2500 to ±6000 psi. The data show a transition from deceleration at the lowest temperatures to significant acceleration at the highest temperatures. This transition occurs at an homologous temperature of about 0.45, but the transition point is not well-defined because the behavior is also slightly dependent upon the stress and strain range. Cyclic creep acceleration or deceleration tends to approach a dynamic equilibrium, and it is shown that this state of equilibrium can be mathematically approximated by a function of the four important variables in reversed creep tests - stress amplitude, strain range, strain rate and temperature. Also, the stress dependence of the average creep rate at equilibrium is found to be similar to that of the minimum tensile creep rate.
Publisher
Department of Theoretical and Applied Mechanics. College of Engineering. University of Illinois at Urbana-Champaign
Series/Report Name or Number
TAM R 674
1974-8514
ISSN
0073-5264
Type of Resource
text
Language
eng
Permalink
http://hdl.handle.net/2142/112378
Sponsor(s)/Grant Number(s)
National Aeronautics & Space Administration 67/08 NGR 14 005 025 67/05
Copyright and License Information
Copyright 1967 Board of Trustees of the University of Illinois
TAM technical reports include manuscripts intended for publication, theses judged to have general interest, notes prepared for short courses, symposia compiled from outstanding undergraduate projects, and reports prepared for research-sponsoring agencies.
Use this login method if you
don't
have an
@illinois.edu
email address.
(Oops, I do have one)
IDEALS migrated to a new platform on June 23, 2022. If you created
your account prior to this date, you will have to reset your password
using the forgot-password link below.
