Investigation of the fatigue life of pre- and post-drilling hole in dog-bone specimen subjected to laser shot peening. (25th December 2015)

• Record Type: Journal Article
• Authors: Zhang, X.Q.; Chen, L.S.; Li, S.Z.; Duan, S.W.; Zhou, Y.; Huang, Z.L.; Zhang, Y.
• Is Part Of: Materials & design. Volume 88(2015:Dec.)
• Page Start: 106
• Page End: 114
• Publication Date: 2015-12-25
• Subjects: C. Laser -- C. Surface treatment -- E. Fatigue -- E. Fracture; Materials -- Periodicals; Engineering design -- Periodicals; Matériaux -- Périodiques; Conception technique -- Périodiques; Electronic journals; 620.11
• DOI: 10.1016/j.matdes.2015.08.136
• Languages: English
• ISSNs: 0264-1275

Abstract

Abstract: The influence of processing sequence of laser shot peening (LSP) on the fatigue properties of fastener hole was investigated with finite element method and experiments. The results show that different processing sequences lead to different residual stress distributions and different fatigue lives. The compressive residual stresses (CRS) are squeezed into two-sided surface layers of fastener hole by two sided laser shot peening, and the ellipse CRS fields are found on both sided surfaces of sample. However, when the pre-drilling hole in dog-bone specimen is subjected to LSP, the tensile stresses appear at its mid-thickness region, while the CRS distribute in the entire thickness region of the post-drilling hole after LSP. The fatigue crack initiation of specimens treated by LSP stems from the subsurface layer of hole edge. The fatigue striation spacing of specimen with post-drilling hole after LSP is narrower in comparison with that of case with pre-drilling hole before LSP. The fatigue life of post-drilling hole is longer than that of the pre-drilling hole. Graphical abstract: Highlights: Compressive residual stresses (CRS) appear at both sides of hole induced by laser. CRS are also found in mid region of post-drilling hole subjected to laser peening. Tensile stresses arise in mid region of pre-drilling hole subjected to laser peening. Fatigue life of the post-drilling hole treated with laser is obviously long.