Bending fatigue strengths/limits of smooth specimens with and without surface‐enhanced layer of aeronautical metallic alloys

Abstract

Purpose

The purpose of this paper is to estimate the bending fatigue strengths/limits of smooth specimens and to quantitatively analyze the effects of residual stresses caused by surface enhancements.

Design/methodology/approach

Rotating bending and three‐point bending fatigue tests were employed to investigate the effects of surface enhancements including shot peening and laser peening on fatigue strengths/limits of smooth specimens. The fatigue sources were determined by scanning electron microscopy (SEM).

Findings

The two new concepts of surface fatigue strength/limit and subsurface fatigue strength/limit were proposed based on experimental results and the relationship of surface fatigue strength/limit to subsurface fatigue strength/limit was built.

Research limitations/implications

This paper provides the estimation that fatigue strengths/limits of surface‐enhanced specimens is 1.34‐1.42 times that of un‐surface‐strengthened specimens for smooth ones without stress concentration.

Originality/value

Based on the present investigation and analysis, an analysis for fatigue strengths/limits of surface‐enhanced smooth specimens can be used to design engineering components, particularly in the applications of aircraft industry.

Citation

Gao, Y. (2011), "Bending fatigue strengths/limits of smooth specimens with and without surface‐enhanced layer of aeronautical metallic alloys", International Journal of Structural Integrity, Vol. 2 No. 3, pp. 357-365. https://doi.org/10.1108/17579861111162941