Mechanistic modelling of worn drill cutting forces with drill wear effect coefficients

When drilling difficult-to-cut materials with twist drills, drill wear frequently occurs with various types including flank wear, crater wear, chisel wear and outer corner wear. The previous research mainly focuses on flank wear. This study presents a mechanistic drilling force model of worn drill with the drill wear effect coefficients (DWECs) to describe the effect of different wear types on drilling forces. The DWECs under different drill wear types are calibrated and analyzed through a group of carefully designed experiments. It believes the proposed model together with the results are useful in drill wear detection.