Dynamic modeling of the turning process of slip-cast fused silica ceramics using the discrete element method

Abstract

Simulation of brittle regime machining of materials (such as ceramics) is often difficult because of the complex material removal mechanisms involved. In this study, the discrete element method is used to simulate the dynamic process for machining of slip-cast fused silica ceramics. Flat-joint contact model is exploited to model contacts between particles in synthetic discrete element method models. This contact model is suitable for modeling of brittle materials with high ratios (higher than 10) of unconfined compressive strength to tensile strength. The discrete element method has the ability to simulate initiation, propagation, and coalescence of cracks leading to chip formation in the brittle regime of cutting. Applying the discrete element method, the influences of operating conditions on the creation of surface/subsurface damages, chip formation, and cutting forces are studied. It is shown that the parameters of the material model determined from conventional calibration tests do not provide quantitatively accurate prediction of cutting forces. As such, model updating is carried out using the forces obtained in the cutting experiments, and the numerical results are verified against experimental cutting forces. The differences between experimental and numerical machining forces are in the range of 10%–30%. Finally, the results of discrete element method simulations reveal that the nature of micro-crack propagation is brittle in the machining process of ceramics.

Discrete element modeling of the machining processes of brittle materials: recent development and future prospective

“…This review paper presents detailed discussions from the application of DEM and its coupling method in the machining simulation of hard-brittle materials. Rojek et al [135]; Su et al [136]; Liu et al [137]; Onate et al [138]; Gong et al [139] Tan et al [19] [79]; Roostai et al [102]; Jiang et al [140] Qiu et al [36]; Alkotami et al […”

“…19. Roostai et al [102] used the flat-joint contact model to construct the quartz ceramics, and carried out a serials of DEM simulation of the dynamic cutting process of the quartz ceramics to study the damages of the surface/subsurface of the workpiece, chip formation and cutting force by different processing parameters. The research results reveal the process of brittle propagation of micro-cracks in the ceramic during cutting.…”

Fatigue failure analysis of ceramic tools in intermittent cutting harden steel based on experiments and finite element method

“…[11][12][13][14] And both experimental and finite-element-based approaches were adopted to research the effect of coated textured tools on cutting performance. 15 FEM was also used to study deep drawing process of SUS304 cups without delayed cracks, 16 the dynamic process for machining of slip-cast fused silica ceramics, 17 and multi-pass non-axisymmetric spinning of cylindrical parts. 18 However, the lifetime and time-dependent mechanical behavior of composites were determined by fatigue crack extension in most of the practical applications.…”