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COMPARISON AMONG THREE
FATIGUE-CREEP INTERACTION LIFE PREDICTION MODELS
AND THEIR APPLICATIONS
CHEN Xuedong1 FAN Zhichao1 CHEN Ling2 JIANG Jialing2 YANG Tiecheng1
(1. National Technology Research Center on
PVP Safety Engineering, Hefei General Machinery Research Institute, Hefei 230031;
2. Research Institute of Chemical Mechanic
Engineering, Zhejiang University, Hangzhou 310027
)
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Abstract: Life prediction methods of fatigue-creep interaction are briefly
reviewed. Three fatigue-creep life prediction models for stress controll mode are introduced, which are based on energy exhaustion, toughness exhaustion, and ductility exhaustion theory respectively. Data from literatures and stress con-trolled fatigue-creep interaction test of 1.25Cr0.5Mo steel with trapezium waveform at 520 ℃ are used to comment on these models and their applicability. The predicting precisions of three models are greatly improved comparing with traditional frequency separation technique(FS) and strain energy frequency modified approach(SEFS). The energy model is applicable to not only stress control mode, but also strain control
mode. The ductility exhaustion model has the best life prediction
precision. The mean strain rate model has very simple form, and can be
applied to all stress controlled failure modes, including pure creep,
pure fatigue and fatigue-creep interaction. The mean strain rate model
extends the applicability of Monkman-Grant relation, and has important engineering value. At last, the application precedure of mean strain rate model is discussed.
Key words: Fatigue Creep Life prediction
Strain energy density Toughness
Ductility Mean strain rate
CLC No: TG142.33
2006年中国机械工程学会年会推荐论文. 国家“十五”科技攻关专题(2004BA803B05-06)、社会公益基金(2004DIB2J051)和安徽省自然科学基金(050450405)资助项目. Received 20061205, received in revised form 20061215
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