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This paper discusses the predictive modeling of a scribing process. The diamond tool geometry is important for this process. As a prototype for the diamond tool, a four-sided pyramid is taken. Some minor changes are made in its geometry in purpose to make the modified tools. The tool geometry is a factor which affects greatly the quality of a final product, its forming, and overall efficiency of the scribing process. Scribing a brittle sheet with the modified tool is studied via parametric finite element modeling (FEM) with aid of the ANSYS software package for computer-aided engineering. The heterogeneous mesh is generated using solid finite elements with a quadratic form function. To obtain more precise simulation and decrease singular effect under force loading conditions, the contact elements and increased density of knots near the tooltip are added in this mesh. The modified variants of the tools are developed to provide a necessary groove quality on a brittle material surface regardless of movement direction. Finally, the algorithm and the corresponding program module for the parametric solution have been created using internal ANSYS APDL programming language. The computation results sufficiently agree with the experimental data obtained in this work and earlier. The calculated stress intensity in the sheet along the normal direction to the surface has large value up to 15 μm from cutting tool tip and decreases more sharply on the surface than in the cross section. So, the approach presented in this paper helps to understand the cutting process and improve machining technology of brittle materials. |
