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Nonlinear Subincremental Method for Determination of Elastic-Plastic-Creep Behaviour

Ottosen, Niels Saabye LU and Gunneskov, O. (1985) In Int. Journal for Numerical Methods in Engineering 21(12). p.2237-2256
Abstract
The frequently used subincremental method has so far been based on a linear interpolation of the total strain path within each main step. This method has proven successful when elastic–plastic behaviour and secondary creep is involved. The present paper proposes a nonlinear subincremental method applicable to general elastic–plastic–creep behaviour including problems with a highly nonlinear total strain path caused by the occurrence of creep hardening. This nonlinear method degenerates to the linear-approach for elastic–plastic behaviour and when secondary creep is present. It is also linear during step loadings and it becomes increasingly more nonlinear, the more creep hardening deformations dominate the behaviour. A wide range of... (More)
The frequently used subincremental method has so far been based on a linear interpolation of the total strain path within each main step. This method has proven successful when elastic–plastic behaviour and secondary creep is involved. The present paper proposes a nonlinear subincremental method applicable to general elastic–plastic–creep behaviour including problems with a highly nonlinear total strain path caused by the occurrence of creep hardening. This nonlinear method degenerates to the linear-approach for elastic–plastic behaviour and when secondary creep is present. It is also linear during step loadings and it becomes increasingly more nonlinear, the more creep hardening deformations dominate the behaviour. A wide range of structures are analysed and the results from both subincremental methods are compared; the nonlinear strategy increases the accuracy by a factor of typically 3–5 without affecting the computer time. Moreover, the implementation of the nonlinear method is extremely simple. The optimum number of substeps in each main step is found to be around 5. For such a choice, the advantage of using the subincremental method as compared to the more conventional solution technique, where only one type of time step is used, is a significant reduction in computer time without, in practice, affecting the accuracy. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Int. Journal for Numerical Methods in Engineering
volume
21
issue
12
pages
2237 - 2256
publisher
John Wiley & Sons
external identifiers
  • scopus:0022388478
DOI
10.1002/nme.1620211209
language
English
LU publication?
yes
id
6d04b495-9552-4841-a382-845aa9ad0fd2 (old id 1370209)
date added to LUP
2010-09-18 11:13:30
date last changed
2017-01-01 07:56:37
@article{6d04b495-9552-4841-a382-845aa9ad0fd2,
  abstract     = {The frequently used subincremental method has so far been based on a linear interpolation of the total strain path within each main step. This method has proven successful when elastic–plastic behaviour and secondary creep is involved. The present paper proposes a nonlinear subincremental method applicable to general elastic–plastic–creep behaviour including problems with a highly nonlinear total strain path caused by the occurrence of creep hardening. This nonlinear method degenerates to the linear-approach for elastic–plastic behaviour and when secondary creep is present. It is also linear during step loadings and it becomes increasingly more nonlinear, the more creep hardening deformations dominate the behaviour. A wide range of structures are analysed and the results from both subincremental methods are compared; the nonlinear strategy increases the accuracy by a factor of typically 3–5 without affecting the computer time. Moreover, the implementation of the nonlinear method is extremely simple. The optimum number of substeps in each main step is found to be around 5. For such a choice, the advantage of using the subincremental method as compared to the more conventional solution technique, where only one type of time step is used, is a significant reduction in computer time without, in practice, affecting the accuracy.},
  author       = {Ottosen, Niels Saabye and Gunneskov, O.},
  language     = {eng},
  number       = {12},
  pages        = {2237--2256},
  publisher    = {John Wiley & Sons},
  series       = {Int. Journal for Numerical Methods in Engineering},
  title        = {Nonlinear Subincremental Method for Determination of Elastic-Plastic-Creep Behaviour},
  url          = {http://dx.doi.org/10.1002/nme.1620211209},
  volume       = {21},
  year         = {1985},
}