Author(s)

Sichuan Jia

Affiliation(s)

School of Engineering Science, University of Chinese Academy of Sciences, Beijing 100049, China.

Corresponding Author

Sichuan Jia

ABSTRACT

Using the improved Tanaka-Mura model, the equivalent conversion relationship between complex fatigue load and tension-compression fatigue load is determined, and the influence law of residual compressive stress is given. The fatigue life and crack origin location of samples were systematically analyzed numerically. The results show that: the fatigue nucleation life and position of the notched specimen are related to the thickness of the strengthening layer, the hardness ratio of the surface to the matrix and the residual stress; the change of the thickness of the strengthening layer will change the crack nucleation position; there is a critical thickness, when the thickness of the strengthening layer is less than the critical thickness, the crack nucleates at the interface between the strengthened layer and the matrix, otherwise, it nucleates at the strengthened subsurface or surface; the increase in the hardness ratio of the surface to the matrix will lead to an increase in the critical thickness; the residual compressive stress has little effect on the fatigue initiation life, while the residual Tensile stress significantly reduces the fatigue initiation life.

KEYWORDS

Surface strengthening treatment; Fatigue life; Fatigue initiation; Stress concentration factor; Notch.

CITE THIS PAPER

Sichuan Jia. Numerical study on fatigue life of notched specimen with surface gradient strengthening. World Journal of Materials Science. 2023, 1(1): 1-6.

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