Pragmatic optimisation methods for determining material constants of viscoplasticity model from isothermal experimental data

Rouse, James Paul; Hyde, Christopher J.; Sun, W.; Hyde, T.H.

Abstract

A procedure to estimate material constants for the unified Chaboche viscoplasticity model from experimental data has been published elsewhere; however several critical assumptions are made to enable this and potential numerical problems can limit the effectiveness of the optimisation. Pragmatic optimisation procedures are therefore required to determine the material properties accurately and efficiently. This is made more complex by the presence of several deformation mechanisms and their interactions. Automation is critical due to the large amounts of data generated in testing. Complications that inhibit this process can arise due to factors such as experimental scatter. In this paper, a general optimisation framework is discussed and investigated using data from isothermal tests on a P91 steel at 600°C. Potential obstacles in the procedure are addressed and solutions (such as pre-optimisation experimental data ‘cleaning’) are suggested. Methods to maximise the amount of confidence a user has in a particular optimised constant set are also discussed.

Citation

Rouse, J. P., Hyde, C. J., Sun, W., & Hyde, T. (in press). Pragmatic optimisation methods for determining material constants of viscoplasticity model from isothermal experimental data. Materials Science and Technology, 30(1), https://doi.org/10.1179/1743284713Y.0000000277

• Journal Article Type: Article
• Acceptance Date: Apr 20, 2013
• Online Publication Date: Dec 6, 2013
• Deposit Date: Sep 19, 2017
• Publicly Available Date: Sep 19, 2017
• Journal: Materials Science and Technology
• Print ISSN: 0267-0836
• Electronic ISSN: 1743-2847
• Publisher: Taylor & Francis Open
• Peer Reviewed: Not Peer Reviewed
• Volume: 30
• Issue: 1
• DOI: https://doi.org/10.1179/1743284713Y.0000000277
• Keywords: Chaboche, Visco-plasticity model, Low cycle fatigue, Optimisation, P91
• Public URL: https://nottingham-repository.worktribe.com/output/720537
• Publisher URL: https://doi.org/10.1179/1743284713Y.0000000277
• Additional Information: This is an Accepted Manuscript of an article published by Taylor & Francis in Materials Science and Technology on 06/12/2013, available online: http://www.tandfonline.com/10.1179/1743284713Y.0000000277