Energy Conversion and Partition in Machining Fiber Reinforced Polymer (FRP) Composites

Cutting temperatures during machining are of a particular importance due to its controlling influence on the quality of machined part as well as tool life. Limited understanding and background on this topic for fiber reinforced polymer composites (FRPs) may perhaps be credited to limitless variations of such materials due to layup, fiber orientation, constituent content etc., which are additional to the usual challenges encountered in heat partition evaluation in machining. Direct measurement of the temperatures in this regard is not always possible due to the highly localized temperatures and the unique tribological contact between the tool and the workpiece. Thus, inverse conduction methods are very appealing for studying the heat transfer problem in a wide variety of machining operations. This chapter presents a complete methodology to evaluate the amount of heat dissipated through workpiece, tool and chips during machining of FRPs using an iterative inverse heat conduction technique. Temperatures are measured experimentally and used as boundary conditions. The transient heat conduction problem in the FRP laminate was simulated using the finite element method and the amount of heat flux conducted through the machined surface, cutting tool and chips was determined. Heat partition in two most commonly known FRPs namely CFRP and GFRP subjected to edge trimming operation are presented. It was observed that smaller fraction of the total heat energy is evacuated through the work piece as compared to the tool and chips. CFRP chips carry away more heat as compared to GFRPs. Moreover, cutter type has insignificant effect on the amount of heat dissipated to the work piece.