Mechanical model for predicting thrust and torque in vibration drilling fibre-reinforced composite materials

Delamination is a dramatic problem associated with drilling fibre-reinforce d composite materials (FRCMs), which, in addition to reducing the structura l integrity of the material, also results in poor assembly tolerance and ha s the potential for long-term performance deterioration. The key to solving the problem lies in reducing the thrust force of drilling. In this paper, a theoretical analysis for predicting mean Values of thrust and torque in v ibration drilling FRCMs is presented. The model is based on mechanics of vi bration cutting analysis and the continuous distributions of thrust and tor que along the lip and the chisel edge of a twist drill. The result of a sim ulation study has shown a very good agreement between the theoretical predi ctions and the experimental evidence. On the same cutting conditions, the t hrust and the torque by the vibration drilling method are reduced by 20-30 percent, compared with conventional drilling. (C) 2001 Elsevier Science Ltd . All rights reserved.