PSI - Issue 57

Dr.-Ing. D. Jbily et al. / Procedia Structural Integrity 57 (2024) 199–216 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

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peening applied is UFS100, 6 bars, angle 30° (simple shot peening - 200% coverage) and the parameters of process are shown in Fig. 1.

Fig. 1. Schematic diagram of the gears shot peening process

2.2. Gear surface characteristics Residual stress analysis was carried out in accordance with standard EN 15305 (2009) on Test methods for residual stress analysis by X-ray diffraction. The calculations were carried out using StressDiff software using the sin²  method with a centred barycentre peak location method developed by CETIM for biaxial calculations. Fig. 2 shows that the residual stresses profile of the non-peened teeth shows a very high stress gradient on the surface (- 600MPa to -250MPa over a depth of 10µm) characteristic of the grinding operation. Shot peening increases the residual stresses in the surface layer over a greater depth up to about 40µm and in a less abrupt way.

Depth (µm)

-800 -600 -400 -200 0

0

20

40

60

80

100

120

-1400 -1200 -1000

Residual stresses (MPa)

SP(longitudinal stresses) REF (longitudinal stresses)

SP (radial stresses) REF (radial stresses)

Fig. 2. Residual stresses in the un-peened (REF) and shot peened (SP) conditions