Characterizing crack growth behavior and damage evolution in P92 steel under creep-fatigue conditions
Autor: | Zhifang Gao, Lianyong Xu, Lei Zhao, Hongyang Jing, Yongdian Han |
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Rok vydání: | 2017 |
Předmět: |
Materials science
business.industry Mechanical Engineering Constitutive equation 02 engineering and technology Structural engineering Creep fatigue 021001 nanoscience & nanotechnology Condensed Matter Physics Crack growth resistance curve Finite element method Crack closure Dwell time 020303 mechanical engineering & transports 0203 mechanical engineering Creep Mechanics of Materials mental disorders General Materials Science Growth rate Composite material 0210 nano-technology business Civil and Structural Engineering |
Zdroj: | International Journal of Mechanical Sciences. 134:63-74 |
ISSN: | 0020-7403 |
Popis: | The present paper characterized crack growth behavior and damage evolution in P92 steel under creep-fatigue interaction conditions. Creep-fatigue crack growth tests were conducted at a constant load amplitude with various hold times. To reveal the role of constraint in creep-fatigue regime, specimens with different crack depths and thicknesses were used. Combination with a non-linear creep-fatigue interaction damage constitutive model, the crack growth and damage evolution behaviors were simulated using finite element method. Under creep-fatigue condition, time dependent crack growth rate increased as the duration period was reduced. This was attributed to the role of enhanced fatigue damage with the decreasing of the dwell time. Moreover, the deviation of crack growth rate with different dwell times became small as crack grew. With the crack length increasing, the creep damage level was improved regardless the dwell time, which may be due to the fact that the creep damage dominated crack growth in this stage. Furthermore, the crack growth rate increased as the crack depth became deep and the specimen thickness became large, as a result of the increased constraint level. A load-independent constraint parameter Q * was introduced to correlate the crack growth rate, which provided a good prediction for specimens under different constraint conditions. |
Databáze: | OpenAIRE |
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