Finite element modelling study on small-hole peck drilling of SiCp/Al composites

In this paper, a 3D finite element model for simulating the 3-mm-diameter peck drilling behavior of SiCp/Al composites was developed by using commercial code ABAQUS/Explicit. In order to improve the calculation accuracy, the proposed model incorporates a real drill by reverse engineering, a Johnson-Cook model developed for SiCp/Al composites, the damage initiation for chip separation, and characteristic-length related damage evolution for representing strain-softening behavior after damage initiation. The FE model is verified with the corresponding small-hole wet peck drilling experiments in terms of thrust force and torque. Then, the model is used to study on the influence of edge radius on the chip formation. The predicted chip is divided into two segments due to the sharp intersection of two curved edges of lips, and this is in good consistency with the actual chips from the experiment. At last, the formation of edge defects is analyzed by a modified FE model. The actual edge defect formation is determined by the random distribution of SiC particles and complicated crack types and opening theory. This necessitates the establishment of microstructure-based model in the future.