FGH97缺口试样基于黏塑性本构的弹塑性响应分析

袁善虎; 魏大盛; 王延荣

FGH97缺口试样基于黏塑性本构的弹塑性响应分析

北京航空航天大学能源与动力工程学院,北京 100191

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出版历程
- 收稿日期: 2012-02-13
- 刊出日期: 2012-10-28

Analysis of elastoplastic response in FGH97 notched specimens based on viscoplastic constitutive model

School of Jet Propulsion, Beijing University of Aeronautics and Astronautics,Beijing 100191,China

摘要

摘要: 针对缺口试样在高温条件下局部区域应力应变难于测量的问题,基于光滑试样材料力学性能试验,优化得到550℃粉末高温合金FGH97的Chaboche黏塑性统一本构方程参数,并将其应用到FGH97缺口试样单调拉伸及循环加载弹塑性有限元分析中.研究结果表明:①缺口局部区域进入塑性后其应力分布与弹性条件明显不同,随应力增大,最大应力位置向内移动;②在循环载荷条件下,随着循环数的增加,缺口平分线上应力/应变范围变化不大,缺口根部塑性区域出现明显平均应力松弛,并逐渐趋于稳定,导致缺口根部循环载荷比不同于外部施加载荷;③缺口根部塑性区域逐渐增大,但增大的幅度逐渐降低.该研究可为进一步分析缺口构件疲劳寿命影响因素提供支持.
- 粉末高温合金 /
- 黏塑性本构模型 /
- 缺口疲劳 /
- 循环应力应变特征 /
- 弹塑性分析
Abstract: In order to solve the difficulties in measuring local stress and strain,the parameters of Chaboche viscoplastic constitutive equations for powder metallurgy super alloy FGH97 at 550℃,which were obtained based on the experiments of material mechanical properties,were used in the elastoplastic FEM (finite element method) analysis of notched specimens subjected to tensile and cyclic loading.The results show that:(1) plastic stress/strain state at notch root is obviously different from elastic one.With the increase of stress,location of maximum stress moves inside.(2) Under cyclic loading,with the increase of cyclic number,the stress and strain range along symmetric path at notch root changes little.Mean stress relaxation occured in the plastic zone at notch root gradually turns to be stable,and it also leads to different cyclic stress ratios compared with the applied load.(3) The plastic zone at notch root gradually increases,but the increasing range gradually decreases.The research result can provide support to further analysis of influencing factors which affect fatigue life of FGH97 notched specimens.
- powder metallurgy superalloy /
- viscoplastic constitutive model /
- notched fatigue /
- characteristics of cyclic stress-strain /
- elastoplastic analysis

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参考文献(14)

[1]	Pfouts W R,Shamblen C E,Mosier J S,et al.Materials for advanced turbine engines:volume 1 power metallurgy rene 95 rotating turbine engine Parts .NASA-CR-159802,1979.
[2]	邹金文,汪武祥.粉末高温合金研究进展与应用[J].航空材料学报,2006,26(3):244-250. ZOU Jinwen,WANG Wuxiang.Development and application of P/M superalloy[J].Journal of aeronautical materials,2006,26(3):244-250.(in Chinese)
[3]	王元清,武延民,石永久,等.含缺口受拉平板塑性应力场的有限元分析[J].工程力学,2007,24(4):7-12. WANG Yuanqing,WU Yanmin,SHI Yongjiu,et al.FEM analysis for plastic stress field of tensile flat slab with crackles[J].Engineering Mechanics,2007,24(4):7-12.(in Chinese)
[4]	Filippini M.Stress gradient calculations at notches[J].International Journal of Fatigue,2000,22(5):397-409.
[5]	Adib-Ramezani H,Jeong J.Advanced volumetric method for fatigue life prediction using stress gradient effects at notch roots[J].Computational Materials Science,2007,39(3):649-663.
[6]	王仁,熊祝华,黄文斌.塑性力学基础[M].北京:科学出版社,1982:134-140.
[7]	Chaboche J L.Constitutive equations for cyclic plasticity and cyclic viscoplasticity[J].International Journal of Plasticity,1989,5(3):247-302.
[8]	石多奇.热端部件材料先进粘塑性本构理论与高温多轴疲劳理论研究 .北京:北京航空航天大学,2004. SHI Duoqi.Viscoplastic constitutive modeling and multiaxial fatigue life prediction of nickel-based superalloy at elevated temperature .Beijing:Beijing University of Aeronautics and Astronautics,2007.(in Chinese)
[9]	魏大盛.FGH95粉末高温合金的变形特征及疲劳性能研究 .北京:北京航空航天大学,2006. WEI Dasheng.Investigation on deformation and fatigue characteristic of powder metallurgy superalloy FGH95 .Beijing:Beijing University of Aeronautics and Astronautics,2007.(in Chinese)
[10]	Lu F,XU J Q.Evaluation of cyclic inelastic response in fretting based on unified Chaboche model[J].International Journal of Fatigue,2005,27(9):1062-1075.
[11]	Susmel L.The theory of critical distances:a review of its applications in fatigue[J].Engineering Fracture Mechanics,2008,75(7):1706-1724.
[12]	Yamashita Y,Ueda Y,Kuroki H,et al.Fatigue life prediction of small notched Ti-6AL-4V specimens using critical distance[J].Engineering Fracture Mechanics,2010,77(9):1439-1453.
[13]	Susmel L,Taylor D.An elasto-plastic reformulation of the theory of critical distances to estimate lifetime of notched components failing in the low/medium-cycle fatigue regime[J].Journal of Engineering Materials and Technology,2010,132(2):021002.1-021002.8.
[14]	Qylafku G,Azari Z,Gjonaj M,et al.On the fatigue failure and life prediction for notched specimens[J].Materials Science,1998,34(5):604-618.