Journal of Shanghai Jiao Tong University (Science) ›› 2020, Vol. 25 ›› Issue (2): 266-272.doi: 10.1007/s12204-020-2172-5

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Probability Model of Residual Strength of Materials Under Uncertain Cyclic Load

Probability Model of Residual Strength of Materials Under Uncertain Cyclic Load

GAO Jianxiong (高建雄), AN Zongwen (安宗文), MA Qiang (马强), ZHAO Shendan (赵申诞)   

  1. (1. School of Mechanical and Electronical Engineering, Lanzhou University of Technology, Lanzhou 730050, China; 2. Department of Mechanical Engineering, Shizuoka Institute of Science and Technology, Fukuroi, Shizuoka 437-8555, Japan)
  2. (1. School of Mechanical and Electronical Engineering, Lanzhou University of Technology, Lanzhou 730050, China; 2. Department of Mechanical Engineering, Shizuoka Institute of Science and Technology, Fukuroi, Shizuoka 437-8555, Japan)
  • Online:2020-04-01 Published:2020-04-01
  • Contact: AN Zongwen (安宗文) E-mail:anzongwen@163.com

Abstract: Residual strength is usually used to characterize the degradation rule of material performance under the cyclic load, which is critical to fatigue life prediction as well as reliability assessment of materials. In order to reveal the probability characteristics of residual strength of material under uncertain cyclic load, the relationship between external stress and fatigue life (i.e., the equation of S-N curve) is considered in this study. Firstly, the probability density function of fatigue life under uncertain cyclic load is derived from the probability density function of external stress. Then, a probability model of residual strength is proposed on the basis of a fundamental assumption that the residual strength and the remaining life of material depend on the same damage state. Finally, the validity of the proposed model is verified by an illustrative example. The results indicate that the probability distribution of residual strength of material is affected by both the external factor (i.e., probability characteristics of the load) and the internal factor (i.e., fatigue performance parameters of material).

Key words: residual strength, fatigue life| probability distribution| fatigue damage| uncertain cyclic load

摘要: Residual strength is usually used to characterize the degradation rule of material performance under the cyclic load, which is critical to fatigue life prediction as well as reliability assessment of materials. In order to reveal the probability characteristics of residual strength of material under uncertain cyclic load, the relationship between external stress and fatigue life (i.e., the equation of S-N curve) is considered in this study. Firstly, the probability density function of fatigue life under uncertain cyclic load is derived from the probability density function of external stress. Then, a probability model of residual strength is proposed on the basis of a fundamental assumption that the residual strength and the remaining life of material depend on the same damage state. Finally, the validity of the proposed model is verified by an illustrative example. The results indicate that the probability distribution of residual strength of material is affected by both the external factor (i.e., probability characteristics of the load) and the internal factor (i.e., fatigue performance parameters of material).

关键词: residual strength, fatigue life| probability distribution| fatigue damage| uncertain cyclic load

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