Stress–strain parameter prediction method for AWJ technology from surface topography

Abstract

Abstract The presented publication is based on the interaction of the material core and its surface during the machining process with a hydro abrasive flexible cutting tool (AWJ). In the AWJ technology, a cold cut is generated; therefore, there are no thermal stresses on the newly formed surface and, consequently, no significant internal and residual stresses. The cut is identifiable by directly measurable parameters: depth of cut, deviation of the cut path from the normal plane, and surface roughness. These geometric parameters are interdependent at each cut zone point and simultaneously dependent on a newly proposed, indirectly measurable material parameter, Kplmat. Although the deviation angle of the cutting path from the normal plane increases with increasing depth of cut, the ratio of the “material plasticity” Kplmat and the surface roughness Ra of the cutting surface remains equivalent to the ratio of the depth of cut and the deviation of the cutting path from the normal plane. Based on the proposed concept, an entirely new approach to the problem of material surface integrity is presented by the method of identification of mechanical equivalents and their functional transformation. The solution to the subject problem is based on the fact that the technological process of machined material decomposition specifically and identically “copies” the surface properties of the material, i.e. records its technological inheritance. The material properties can then be “read retrospectively” reliably and accurately using the recording.