On the plastic strain accumulation in notched bars during high-temperature creep dwell
Barbera, Daniele and Chen, Haofeng (2020) On the plastic strain accumulation in notched bars during high-temperature creep dwell. Journal of Mechanics, 36 (2). pp. 167-176. ISSN 1727-7191 (https://doi.org/10.1017/jmech.2019.56)
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Abstract
Structural integrity plays an important role in any industrial activity, due to its capability of assessing complex systems against sudden and unpredicted failures. The work here presented investigates an unex- pected new mechanism occurring in structures subjected to monotonic and cyclic loading at high tempera- ture creep condition. An unexpected accumulation of plastic strain is observed to occur, within the high- temperature creep dwell. This phenomenon has been observed during several full inelastic finite element analyses. In order to understand which parameters make possible such behaviour, an extensive numerical study has been undertaken on two different notched bars. The notched bar has been selected due to its capability of representing a multiaxial stress state, which is a practical situation in real components. Two numerical examples consisting of an axisymmetric v-notch bar and a semi-circular notched bar are consid- ered, in order to investigate different notches severity. Two material models have been considered for the plastic response, which is modelled by both Elastic-Perfectly Plastic and Armstrong-Frederick kinematic hardening material models. The high-temperature creep behaviour is introduced using the time hardening law. To study the problem several results are presented, as the effect of the material model on the plastic strain accumulation, the effect of the notch severity and the mesh element type and sensitivity. All the findings further confirm that the phenomenon observed is not an artefact but a real mechanism, which needs to be considered when assessing off-design condition. Moreover, it might be extremely dangerous if the cyclic loading condition occurs at such a high loading level.
ORCID iDs
Barbera, Daniele and Chen, Haofeng ORCID: https://orcid.org/0000-0001-6864-4927;-
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Item type: Article ID code: 70111 Dates: DateEvent30 April 2020Published21 February 2020Published Online6 August 2019AcceptedSubjects: Technology > Mechanical engineering and machinery Department: Faculty of Engineering > Mechanical and Aerospace Engineering
Strategic Research Themes > Ocean, Air and SpaceDepositing user: Pure Administrator Date deposited: 15 Oct 2019 09:30 Last modified: 27 Nov 2024 01:16 Related URLs: URI: https://strathprints.strath.ac.uk/id/eprint/70111