Research on the effect of material performances ɛ f and Δ ɛ c on the strain fatigue life predication accuracy

Abstract

Fatigue failure occurs for many metal materials, and it affects the product reliability. Therefore, the fatigue life predication is important for metal materials under conditions of heavy and high-speed loading. Presently, many researches have focused on the fatigue life predication and many fatigue life predication methods have been used industrially, such as Manson-Coffin relation and damage strain model. However, few reports can be found on the predication accuracy. Based on Manson-Coffin relation and damage strain model, this paper analyzes the effect of the material performance ɛ_f on the predication accuracy. Furthermore, it is pointed out that single material performance will cause the low calculation accuracy. Then, an improved formula is derived to predicate the strain fatigue life. This formula is related to two material performances ɛ_f and Δɛ_c. Moreover, the predication accuracy analysis is conducted through calculating error. Finally, experiments prove that this formula can greatly improve the calculation accuracy. Therefore, this proposed formula is reliable and reasonable.