MATHEMATICAL MODEL OF SURFACE PROFILE ARITHMETIC MEAN DEVIATION FORMATION AT SHOT PEEN FORMING
Shot peen forming (SPF) is used for forming panels and skins as well as for hardening. As a rule, shot peen forming is performed after milling. The surface roughness obtained as a result of sequential performance of these operations is a complex structure, a combination of an original microrelief and shot peening indentations of different depths and chaotic distribution along the surface. As far as shot peen forming is a random process, the surface roughness resulting from milling and shot-blasing is random too. The PURPOSE of the paper is development of a mathematical dependence model of arithmetic mean deviation of surface roughness profile under shot peen forming. METHOD. A technique is proposed for calculating surface roughness after shot peen forming based on the indentation depth analysis. RESULTS. The analysis of depths and distribution of shot peen indentations along the surface allowed to identify the shift of the original profile center plane and build a mathematical model of the arithmetic mean deviation of the profile surface. Experimental testing proved model validity and determined the inversely proportional dependency of the basic area on the coverage degree.