Modeling Hole Edge and Burr Formation During Drilling Using LS-DYNA

Drilling is one of the most utilized technological processes in machining and manufacturing. Due to its scale, optimizing drilling parameters for increased productivity and quality has an overwhelming impact on manufacturing labor intensity and final product cost and performance. The quality of hole edges and its roughness, including the presence of burrs, are important parameters determining the part quality and might require post-processing for high-performance applications. Thus, optimizing the drilling process for forming holes with minimum roughness and burrs is a critical task and requires a comprehensive understanding of the process. This work investigated the major drilling parameters for hole forming with drill bits of various degrees of wear. Numerical modeling, particularly explicit finite element approach, was validated with the experiment and exploited due to the limitations of experimental tools to observe a full spectrum of internal material behavior during the dynamic process. The results have shown that hole edge burrs and drilling force progressively increased with the larger drill bit wear, while residual strains mostly varied their concentrations and affected larger material volume around the holes.