Comparison of inverse methods in the determination of heat flux and temperature in cutting tool during a machining process
Solidônio R. De Carvalho, Marcelo R. Dos Santos, Priscila F. B. De Souza, Gilmar Guimarães and Sandro M. M. De Lima E Silva
During machining, high temperatures are generated in the region of the tool cutting edge. These temperatures have a controlling influence on the wear rate of the cutting tool and on the friction between the chip and the tool. However, direct measurement of temperature using contact type sensors at the tool-work interface is difficult to implement due to the movement of the workpiece and the presence of the chip. Conventional methods such as infrared pyrometer, embedded thermocouple and tool-work thermocouple usually present problems. The use of inverse heat conduction techniques represents a good alternative since these methods uses temperatures measured in accessible positions. This paper proposes a comparison of the inverse techniques Golden Section, Function Specification, Simulated Annealing and Dynamics Observers Based on Green’s Function. They are used in an experimental methodology to determine the thermal fields and heat generated at the chip-tool interface during machining. A numerical 3-D transient thermal model was developed to consider both tool and tool holder assembly. The results are validated by controlled experiments and qualitative analysis. Some of the cited procedures are in the computational code INV3D that contain a series of functions for the experimental data acquisition, the three-dimensional mesh generation and the graphical environment analysis.
Keywords: Inverse problems, heat conduction, optimization, heat flux identification, machining process.