It has long been recognized that the introduction of compressive residual stress fields is one means of increasing resistance to fatigue. Beneficial residual stresses may be induced using processes such as shot peening and presetting. An additional technique with much potential is water peening. Water peening is similar to shot peening using instead of steel shot, a high velocity water jet to impinge upon the component surface. As a replacement for shot peening, potential advantages of water peening include a better surface finish and increased coverage.
Potential disadvantages are a reduced residual stress depth and magnitude, and surface erosion.
To characterize the water peening process, various pressures and stand-off distances were used to peen 1100 aluminum sheet. The surface residual stresses were measured, and results will be compared with predictions from finite element modeling. In addition, surface roughness and surface hardness were measured. A universal mathematical modeling method for the analysis of torsional, axial and lateral vibrations of power trains is developed. It applies to both linear and nonlinear cases.