Microstructural influence on high temperature creep flow of Zr–1%NbO alloy in near-α, (α+β), and β temperature ranges in a high vacuum environment

2011 ◽  
Vol 408 (1) ◽  
pp. 116-124 ◽  
Author(s):  
Djilali Kaddour ◽  
Anne-Françoise Gourgues-Lorenzon ◽  
Jean-Christophe Brachet ◽  
Laurence Portier ◽  
André Pineau
Keyword(s):  
High Temperature ◽  
High Vacuum ◽  
High Temperature Creep ◽  
Creep Flow ◽  
Temperature Creep ◽  
Temperature Ranges ◽  
High Vacuum Environment

scholarly journals On the Plastic Strain Accumulation in Notched Bars During High-Temperature Creep Dwell

2020 ◽  
Vol 36 (2) ◽  
pp. 167-176 ◽  
Author(s):  
Daniele Barbera ◽  
Haofeng Chen
Keyword(s):  
High Temperature ◽  
Cyclic Loading ◽  
Plastic Strain ◽  
Kinematic Hardening ◽  
High Temperature Creep ◽  
Strain Accumulation ◽  
Material Models ◽  
Cyclic Loading Condition ◽  
Hardening Material ◽  
Temperature Creep

ABSTRACTStructural 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 unexpected new mechanism occurring in structures subjected to monotonic and cyclic loading at high temperature 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 considered, 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.

Investigation of High-Temperature Creep in Mullite – Zirconium Oxide Polydisperse Ceramic

2014 ◽  
Vol 71 (5-6) ◽  
pp. 175-179
Author(s):  
V. G. Maksimov ◽  
D. V. Grashchenkov ◽  
V. A. Lomovskoi ◽  
V. G. Babashov ◽  
O. V. Basargin ◽  
...  
Keyword(s):  
High Temperature ◽  
Zirconium Oxide ◽  
High Temperature Creep ◽  
Temperature Creep
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