Determination of the Stress–Strain State of a Turning Cutter During Mechanical Processing of Sand–Polymer Composites

The machining of highly abrasive sand–polymer composites pose significant challenges due to rapid tool wear directly associated with the tool’s stress–strain state. This study provides a detailed analysis of the stress and strain distribution in a T15K6 carbide turning insert under contact loads generated during the cutting of SPCs with varying quartz content. The approach combines analytically derived contact stress distributions on the rake and flank faces with numerical modeling using the finite element method (ANSYS). This hybrid methodology enables the accurate evaluation of stress localization in critical tool regions without performing full-scale cutting simulations. A parametric series of simulations was carried out by varying the mass fraction of quartz in the composite. The results demonstrate an almost linear increase in the maximum equivalent (von Mises) stress with rising quartz content, described by σeq = 9.61·Cquartz + 232.41. For the base composition with 60% quartz, the maximum equivalent stress is approximately 812 MPa, corresponding to about 50% of the flexural strength of the T15K6 alloy and ensuring a safety margin of roughly two. However, as the quartz fraction approaches 85%, the stress level becomes close to the critical limit, indicating an elevated risk of tool failure. The proposed analytical-numerical approach provides an effective framework for assessing the stress–strain state of carbide cutting tools and can support the optimization of machining conditions for highly abrasive composite materials.