02 Para Gleici - item5-09

02 Para Gleici - item5-09

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ure points used he cutting tool nductivity of resented as gra btained in the ed when the im

7. Estimated h present stud

006) and numer ct thermal resis ble. In this num obtain good elements, the y by consideri by Carvalho e l, shim, and th 26.3e-3 W m aphs. Two grap simulations w mpact of TCR w heat flux used a dy (Brito et. al b) rical temperatu stance b) for th ences and Engin elém, PA, Brazil merical validat accuracy and temperature ing only the c et. al. (2006) w he tool holder, m-1 K-1 accordi phs were plott without TCR v was considered as input data in ., 2014) ure obtained in hermocouple 1 neering tion, it d low value cutting will be when ing to ted for versus d.

n the n the .

Copyright © 2014 by ABCMNovember 10-13, 2014, Belém, PA, Brazil
a)b)

Proceedings of ENCIT 2014 15 Brazilian Congress of Thermal Sciences and Engineering

Figure 9. Comparison between experimental data (Carvalho et. al., 2006) and numerical temperature obtained in the present work without contact thermal resistance a) and with contact thermal resistance b) for thermocouple 2.

a)b)

Figure 10. Comparison between experimental data (Carvalho et. al., 2006) and numerical temperature obtained in the present work without contact thermal resistance a) and with contact thermal resistance b) for thermocouple 3.

a)b)

Figure 1. Comparison between experimental data (Carvalho et. al., 2006) and numerical temperature obtained in the present work without contact thermal resistance a) and with contact thermal resistance b) for thermocouple 4.

a)b)

Figure 12. Comparison between experimental data (Carvalho et. al., 2006) and numerical temperature obtained in the present work without contact thermal resistance a) and with contact thermal resistance b) for thermocouple 5.

Copyright © 2014 by ABCMNovember 10-13, 2014, Belém, PA, Brazil
a)b)

Proceedings of ENCIT 2014 15 Brazilian Congress of Thermal Sciences and Engineering

Figure 13. Comparison between experimental data (Carvalho et. al., 2006) and numerical temperature obtained in the present work without contact thermal resistance a) and with contact thermal resistance b) for thermocouple 6.

a)b)

Figure 14. Comparison between experimental data (Carvalho et. al., 2006) and numerical temperature obtained in the present work without contact thermal resistance a) and with contact thermal resistance b) for thermocouple 7.

a)b)

Figure 15. Comparison between experimental data (Carvalho et. al., 2006) and numerical temperature obtained in the present work without contact thermal resistance a) and with contact thermal resistance b) for thermocouple 8.

The analysis of obtained results revealed that in most monitoring points the curves derived from numerically simulated data were considerably close to the curves produced from experimental data when thermal contact resistance was considered. This finding can be seen more clearly in the graphs shown in Figs. 12 and 13, in which the differences between the two curves were greater. Another noteworthy finding was the difference in results related to how far thermocouples were to the face where TCR was applied. Thermocouple 2, described in Fig. 9, had the worst result. This occurred probably due to the significant distance between the thermocouple and the face where RTC was applied.

Copyright © 2014 by ABCMNovember 10-13, 2014, Belém, PA, Brazil

Proceedings of ENCIT 2014 15 Brazilian Congress of Thermal Sciences and Engineering

Thermocouples 4 and 5, described in Figs. 1 and 12, respectively, showed significant improvements when TCR was considered, and both were positioned directly over the face in which the boundary condition was applied.

6. CONCLUSIONS

This work presented how the heat flux, estimated with inverse problem techniques in past work by Brito et. al. (2014), and numerical temperatures obtained in COMSOL Multiphysics® v4.4 package are close to the experimental model done by Carvalho et. al. (2006) when considering contact resistance between the cutting tool and the shim. Although results were satisfactory, some sources of error have been observed and should be considered in future studies. The most significant were: heat flux used in this study was derived from estimations published in another study; the differences between the actual model and the one used in this study; the fact that the variations of thermal and physical properties of the material with temperature were disregarded. However, TCR yielded significant improvements and should be used in future studies. By considering the need to reduce the cutting tools costs in industry, studies like this can show an effective method to find the optimum temperature field with the use of commercial software packages from which results closer to real are possible to be obtained.

7. ACKNOWLEDGEMENT

The authors would like to thank the Brazilian Federal Agency for the Support and Evaluation of Graduate Education - CAPES for their financial support.

8. REFERENCES

Brito, R.F., Carvalho, S.R., Lima e Silva, S.M.M., 2014. “The use of COMSOL and inverse problem technique to estimate the heat flux on a cutting tool”. In Proceedings of the ICIPE 2014 8th International Conference on Inverse Problems in Engineering, Cracow - Poland, p. 1-10.

Carvalho, S.R., Lima e Silva, S.M.M., Machado, A.R.; and Guimarães, G., 2006. “Temperature determination at the chip-tool interface using an inverse thermal model considering the tool holder”. Journal of Materials Processing Technology, Vol. 179, No. 97.

Chen, G., Ren, C., Zhang, P., Cui, K., and Li, Y., 2013. “Measurement and finite element simulation of micro-cutting temperatures of tool tip and work piece”. International Journal of Machine Tools and Manufacture, Vol. 75, p. 16- 26. E. M. Trent, P. K. Wright, 2000, “Metal Cutting”, Butterworth Heinemann, 4th ed., Woburn, United States. F. P. Incropera, D. P. DeWitt, T. L. Bergman, A. S. Lavine, 2007, “Fundamentals of Heat and Mass Transfer”, 6th ed.,

John Wiley & Sons, USA.

T. C. Jen, G. Gutierrez, 2000, “Numerical Heat Transfer Analysis in Transient Cutting Tool Temperatures”,

Proceedings of 34th National Heat Transfer Conference, Pittsburgh, Pennsylvania, August, p. 20-2.

Smith, T.G., 2011. “Development of a new theory of thermal cutting processes: determining optimal cutting conditions to extend tool life”. Russian Engineering Research, Vol. 31, No. 9, p. 877-879.

Yang, K., Zheng, K., Bai, K., and Chen, W., 2011. “Tool edge radius effect on cutting temperature in micro -end- milling process”. The International Journal of Advanced Manufacturing Technology, Vol. 52, No. 9-12, p. 905- 912. W. Grzesik, P. Niesłony, M. Bartoszuk, 2009, “Modelling of the Cutting Process Analytical and Simulation Methods”, Advances in Manufacturing Science and Technology, Vol. 3, p. 5-29.

9. RESPONSIBILITY NOTICE The authors are the only responsible for the printed material included in this paper.

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