The Almen intensity will provide a certain depth of compression. In this experiment an Almen intensity was established and the depth of compression was measued and declared to be 100% on the flat surface.
Subsequent peening with various ratios of shot size and filet radius were then peened at that given intensity and then the depth of compression was determined by X-ray diffraction. You can see from the chart that when the diameter of the shot was one half of the radius, or a 4 to 1 ratio, then the depth of compression approached the same effect as peening upon a flat surface.
The purpose of the experiment was to reconfirm the specification requirement that the shot diameter be no larger than one half of the filet radius. The particular intensity chosen is not important (as long as it remains constant for the entire experiment). The peenig effect (depth of compression)was shown to vary with the ratio, as expected.
