A micro–macro combined approach using FEM for modelling of machining of FRP composites: Cutting forces analysis

Experimental investigation of machining is cost prohibitive. The number of parameters to control, the exhaustive material characterisation and the time consuming procedure to determine the mechanical responses like cutting forces restricts experimental studies. In this context, finite element analysis can be a feasible tool for studying the various responses in machining. This paper presents an attempt to investigate orthogonal Machining of Unidirectional Glass Fibres Reinforced Plastics (UD-GFRP) using Finite Element (FE) simulation. The simulation uses the Tsai-Hill theory to characterise failure in plane stress conditions and orthotropic behaviour. The model incorporates adaptive mesh technique and density. The material is modelled as an Equivalent Orthotropic Homogeneous Material (EOHM). A simulation scheme entailing fibre orientation, depth of cut and tool rake angle is constructed for investigating the cutting and thrust force developed during machining. The numerical results are compared to [Nayak D, Bhatnagar N, Mahajan P. Machining studies of UD-FRP composites – part 1: effect of geometrical and process parameters, Mach Sci Technol 2005;9:481–501; Nayak D, Bhatnagar N, Mahajan P. Machining studies of UD-FRP composites – part 2: finite element analysis, Mach Sci Technol 2005;9:503–528.]. Comparison indicates that the model provides satisfactory prediction of the cutting forces. The relations between material properties, tool geometry and process parameters are discussed.