Prediction model of chisel edge thrust force and material damage mechanism for interlaminar-direction drilling of UD-CFRP composite laminates

Abstract

Interlaminar-direction drilling of carbon fiber reinforced plastic (CFRP) is a new machining mode different from the conventional drilling. The thrust force on chisel edge of interlaminar-direction drilling is a key factor for the machining quality of CFRP. Therefore, it is necessary to accurately predict the thrust force on chisel edge, and reveal the material damage mechanism for the study of CFRP interlaminar-direction drilling. In this work, the chisel edge of the conventional twist drill is divided into two parts: the cutting edge and the rake face. By respectively establishing the thrust force models of the cutting edge and the rake face, the prediction model of the thrust force of chisel edge for interlaminar-direction drilling of unidirectional CFRP (UD-CFRP) is established. The reliability of the prediction model is verified by the designed experiments. Moreover, the response law of the thrust force of chisel edge to the machining parameters is discussed in detail, and the material damage mechanisms under the action of chisel edge and main cutting edge are revealed by micro characterization of materials. This study is expected to enrich the theory of interlaminar-direction drilling of CFRP, and provide a theoretical basis for guiding the strategy about interlaminar-direction drilling of CFRP.