Numerical study on the chip removal and surface quality of CFRP/Ti6Al4V stacks

Abstract

Machining of multilayer stacks constituted by carbon fibre reinforced polymer (CFRP) composites and titanium (Ti) alloys has been a hot topic receiving extensive attention in both academia and industry due to their superior mechanical properties and widespread applications in the modern aircraft. Compared with the wide availability of experimental studies dealing with the cutting of CFRP/Ti6Al4V stacks, the present work aims to utilize a finite element (FE) method to address fundamentally the machining characteristics of this metallic-composite material. In this paper, a two-dimensional numerical model of orthogonal cutting configuration has been established to improve the mechanism investigations of the bi-material cutting process. The CFRP/Ti6Al4V model has been constructed by establishing three different physical constituents including the Ti phase, the interface and the CFRP phase. Disparate constitutive laws and damage criteria have been implemented to build the anisotropic machinability of the sandwich material. The key cutting phenomena including the chip removal process, machined surface quality and parametric effects on the stack cutting response have been addressed with a particular focus on the quantification of the machining-induced composite damage. The numerical analysis sheds light on several implicit mechanisms dominating the stack machining and offers a better CFRP/Ti6Al4V cutting understanding.