Modeling of abrasive waterjet machining (AWJM) has been finding widespread interest for the past twenty years. Due to the complex interaction of several AWJM parameters, combined with the nonlinear dynamic high speed impact of several thousands of small abrasive particles on the workpiece surface, the mechanism of material removal has not yet been fully understood. The current paper presents an attempt to explain the mechanism of material removal in AWJ, as a result of abrasive particle impact through step by step tracing of the abrasive particle as it is interacting with the workpiece material. The new model considers the elastic-plastic behavior of the workpiece material. Also the non linear dynamic loading conditions which are characteristic feautres of AWJM are accounted for in the pesent study. The failure of the workpiece material is examined analytically, by means of a virtual finite element (FE) AWJ experiment, and experimentally, by means of scanning electron microscopy (SEM) and surface topographies. Stress results indicate that the workpiece material is subject to severe highly localized plastic deformation and as a result, small overlapping craters are generated. These craters are formed by high compressive stresses at the cutting interface. The finite element results indicate a good agreement with experimental results. |
