Multiaxial fatigue life modeling based on stress gradient and additionalhardening

Abstract

Abstract: Considering the influence of non-uniform stress field and non-proportional additional hardening on the fatigue damage evolution process, a fatigue life prediction model for multiaxial notched specimens is established to solve the problem that the stress gradient and additional hardening effect are not considered in Manson-Coffin equation. Firstly, considering the physical mechanism of crack initiation and propagation, the location of the critical plane is determined by using the maximum shear strain amplitude as the damage parameter based on the coordinate transformation principle and the critical plane theory. Secondly, the normal stress and shear stress on the critical plane are normalized, and the new equivalent stress gradient factor is determined considering the multiaxial stress concentration factor and stress gradient influence index. Meanwhile, taking into account the influence of phase difference, path non-proportion, and material non-proportion on fatigue life, a new non-proportional additional hardening factor is proposed. Finally, a new multiaxial fatigue life prediction model is proposed based on the Manson-Coffin equation. The prediction life of the proposed model, Manson-Coffin equation, LV model, and FS model are compared with the experimental results. The comparison results show that the prediction accuracy of the proposed model is better than the other three models.

Key words: multiaxial notched specimens, stress gradient effect, non-proportional additional hardening, fatigue life prediction, critical plane method

CLC Number:

TH114

LIU Jian-hui, WANG Jie, HUA Fei-long, ZHAO He. Multiaxial fatigue life modeling based on stress gradient and additionalhardening[J]. Journal of Lanzhou University of Technology, 2024, 50(4): 43-49.

References

[1] 金丹,缑之飞.缺口件疲劳寿命预测新方法 [J].航空材料学报, 2017,37(2):81-87.
[2] ZHENG M L,LI P,YANG J G,et al.Fatigue life prediction of high modulus asphalt concrete based on the local stress-strain method [J].Applied Sciences-Basel,2017,7(3):1-17.
[3] ZHU S P,HE J C,LIAO D,et al.The effect of notch size on critical distance and fatigue life predictions [J].Materials and Design,2020,196(1):109095.
[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] YAO W X,XIA K Q,GU Y.On the fatigue notch factor,K_f[J].International Journal of Fatigue,1995,17(4):245-251.
[7] BROWN M W,MILLER K J.A theory for fatigue failure under multiaxial stress-strain conditions [J].Archive:Proceedings of the Institution of Mechanical Engineers,1973,187:745-755.
[8] 李训涛,廖霞霞,胡明敏.基于塑性应变能复杂应力场非比例加载疲劳寿命分析 [J].力学季刊,2017,38(2):345-350.
[9] LUO P,YAO W X,SUSMEL L,et al.A survey on multiaxial fatigue damage parameters under non-proportional loadings [J].Fatigue and Fracture of Engineering Materials and Structures,2017,40(9):1323-1342.
[10] 何国求,陈成澍,高庆,等.基于微结构分析定义应变路径非比例度 [J].金属学报,2003,39(7):715-720.
[11] 韩庆华,王培鹏,芦燕.考虑全平面损伤参量的多轴低周疲劳预测方法研究 [J].天津大学学报(自然科学与工程技术版),2018,51:49-56.
[12] 于良,白菊丽,肖林.Zr-4合金双轴加载中的非比例附加软化与附加强化 [J].西安交通大学学报,2004,38(3):299-302.
[13] MEGGIOLARO M A,WU H,PINHO-DE-CASTRO J T.Non-proportional hardening models for predicting mean and peak stress evolution in multiaxial fatigue using Tanaka’s incremental plasticity concepts [J].International Journal of Fatigue,2016,82:146-157.
[14] PAUL S K.Prediction of non-proportional cyclic hardening and multiaxial fatigue life for FCC and BCC metals under constant amplitude of strain cycling [J].Materials Science and Engineering A,2016,656:111-119.
[15] HUANG Y H,TU S T,XUAN F Z.Pit to crack transition behavior in proportional and non-proportional multiaxial corrosion fatigue of 304 stainless steel [J].Engineering Fracture Mechanics,2017,184:259-272.
[16] 赵而年,瞿伟廉.一种新的多轴非比例低周疲劳寿命预测临界面模型 [J].力学学报,2016,48(4):944-952.
[17] 刘俭辉.基于损伤力学-临界面法的多轴疲劳寿命预估方法研究 [ D].西安:西北工业大学,2015.
[18] 王延荣,李宏新,袁善虎,等.考虑应力梯度的缺口疲劳寿命预测方法 [J].航空动力学报,2013,28(6):1208-1214.
[19] 钟波,王延荣,魏大盛,等.基于应变路径非比例度的多轴疲劳寿命预 [J].航空动力学报,2016,31(2):317-322.
[20] 董志航,廖志忠.理论应力集中系数的有限元求法 [J].航空兵器,2005(3):15-18.
[21] SOCIE D F,SHIELD T W.Mean stress effects in biaxial fatigue of inconel 718 [J].Journal of Engineering Materials and Technology,1984,106:3(3):227-232.
[22] 尚德广,王德俊.多轴疲劳强度 [M].北京:科学出版社,2007.
[23] CHEN X,GAO Q,SUN X F.Low-cycle fatigue under non-proportional loading [J].Fatigue and Fracture of Engineering Materials and Structures,1996,19(7):839-854.
[24] 孙国芹.高温多轴疲劳行为及寿命预测 [D].北京:北京工业大学,2009.
[25] BORODII M V,SHUKAEV S M.Additional cyclic strain hardening and its relation to material structure,mechanical characteristics,and lifetime [J].International Journal of Fatigue,2007,29(6):1184-1191.
[26] 刘俭辉,华飞龙,段红燕,等.考虑应力梯度及附加强化的多轴疲劳寿命预测 [J].华中科技大学学报(自然科学版),2021,49(9):59-63.
[27] 吴志荣.钛合金多轴疲劳寿命预测方法研究 [D].南京:南京航空航天大学,2014.
[28] GAN L,WU H,ZHONG Z.Use of an energy-based/critical plane model to assess fatigue life under low-cycle multiaxial cycles [J].Fatigue and Fracture of Engineering Materials and Structures,2019,45(2):2694-2708.