An Integral Method to Determine Workpiece Flow Stress and Friction Characteristics in Metal Cutting
Norfariza Wahab*, Yumi Inatsugu**, Satoshi Kubota**, Soo-Young Kim**, and Hiroyuki Sasahara*
*Tokyo University of Agriculture and Technology
2-24-16 Naka-cho, Koganei-shi, Tokyo 184-8588, Japan
** Yamanaka Eng. Co., Ltd.
2-11-2 Osaku Sakura-shi, Chiba 285-0802, Japan
In recent times, numerical simulation techniques have been commonly used to estimate and predict machining parameters such as cutting forces, stresses, and temperature distribution. However, it is very difficult to estimate the flow stress of a workpiece and the friction characteristics at a tool/chip interface, particularly during a high-speed cutting process. The objective of this study is to improve the accuracy of the present method and simultaneously determine the characteristics of the flow stress of a workpiece and friction at the cutting edge under a high strain rate and temperature during the cutting process. In this study, the Johnson-Cook (JC) flow stress model is used as a function of strain, strain rate, and temperature. The friction characteristic was estimated by minimizing the difference between the predicted and measured results of principal force, thrust force, and shear angle. The shear friction equation was used to estimate the friction characteristics. Therefore, by comparing the measured values of the cutting forces with the predicted results from FEM simulations, an expression for workpiece flow stress and friction characteristics at the cutting edge during a high-speed cutting process was estimated.
-  B. Wang and Z. Liu, “Shear localization sensitivity analysis for Johnson-Cook constitutive parameters on serrated chips in high speed machining of Ti6Al4V,” Simulation Modeling Practice and Theory, Vol.55, pp. 63-76, 2015.
-  P. Chevrier, A. Tidu, B. Bolle, P. Cezard, and J. P. Tinnes, “Investigation of surface integrity in high-speed end milling of a low alloyed steel,” International Journal Machine Tools & Manufacture, Vol.43, pp. 1135-1142, 2003.
-  S. Ekinovic, S. Dolinsek, and I. S. Jawahir, “Some observations of the chip formation process and the white layer formation in high speed milling of hardened steel,” Machining Science and Technology: An International Journal, Vol.8, No.2, pp. 327-340, 2004.
-  J. Limido, C. Espinosa, M. Salaun, and J. L. Lacome, “SPH method applied to high speed cutting modeling,” International Journal of mechanical Sciences, Vol.49, pp. 898-908, 2007.
-  H. K. Töonshoff, W. Bussmann, and C. Stanske, “Requirements on, Process modeling in machining,” Proceedings of the 26th International Machine tool and Research Conference, pp. 349-357, 1986.
-  C. J. Salomon, “Process for the Machining of Metals or Similarly Acting Materials When Being Worked by Cutting Tools,” German Patent, No.523594, 1931-04.
-  G. List, G. Sutter, X. F. Bi, A. Molinari, and A. Bouthiche, “Strain, strain rate and velocity fields determination at very high cutting speed,” Journal of Materials Processing Technology, Vol.213, pp. 693-699, 2013.
-  R. S. Pawade and S. S. Joshi, “Mechanism of chip formation in high-speed turning of Inconel 718,” Mach. Sci. Tech., Vol.15, 132-152, 2011.
-  M. Shatla, C. Kerk, and T. Altan, “Process modeling in machining. Part I: determination of flow stress data,” International Journal of Machine Tools & Manufacture, Vol.41, pp. 1511-1534, 2001.
-  M. Shatla, C. Kerk, and T. Altan, “Process modeling in machining. Part II: validation and applications of the determined flow stress data,” International Journal of Machine Tools & Manufacture, Vol.41, pp. 1659-1680, 2001.
-  P. Sartkivanich, F. Koppka, and T. Altan, “Determination of flow stress for metal cutting simulation a progress report,” Journals of Materials Processing Technology, Vol.146, pp. 61-71, 2004.
-  N. Wahab, Y. Inatsugu, S. Kubota, S.-Y. Kim, and H. Sasahara, “Identification of flow stress applicable for FEM simulation of orthogonal cutting process,” Key Engineering Materials, Vol.625, pp. 378-383, 2014.
-  C. Shet and X. Deng, “Finite element analysis of orthogonal metal cutting process,” Journal Materials Processing Technology, Vol.105, pp. 95-109, 2000.
-  G. R. Johnson and W. H. Cook, “A constitutive model and data for metals subjected to large strains, high strain rates and temperatures,” Proceedings of the 7th International Symposium on Ballistic, pp. 541-547, 1983.
-  T. H. C. Childs, K. Maekawa, T. Obikawa, and Y.. Yamane, “Metal Machining: Theory and Applications,” Butterworth-Heinemann, Vol.176, 2000.
-  T. ”Ozel and T. Altan, “Modeling of High Speed Machining Processes for Predicting Tools Forces, Stresses and Temperatures using FEM Simulations,” Proceedings of the CIRP International Workshop on Modeling of Machining operations, pp. 225-234, 1998.
-  T. ”Ozel and E. Zeren, “Determination of work material flow stress and friction for FEA of machining using orthogonal cutting tests,” Journal of Materials Processing Technology, pp. 153-154, pp. 1019-1025, 2004.
-  O. S. Rafal, “Constitutive behavior of aluminum alloy sheet at high strain rates,” Master of Applied Science in Mechanical Engineering, Vol.55, 2005.
-  Shirakashi, Modern cutting theory, Kyouritsu Shuppan Co. LTD, Vol.57, 1990 (in Japanese).
-  G. Boothroyd, “Fundamentals of Metal Machining and Machine Tools,” International student edition, Vol.63, 1981.
-  C. Z. Duan, T. Dou, Y. J. Cai, and Y. Y. Li, “Finite element simulation and experiment of chip formation process during high speed machining AISI 1045 hardened steel,” 02, AMAE Int. J. on production and industrial engineering, pp. 28-32, 2011.
-  Shirakashi, Modern cutting theory, Kyouritsu Shuppan Co. LTD, Vol.60, 1990 (in Japanese).
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