A newly-developed model for predicting cutting power during wood sawing with circular saw blades
Keywords:
Circular sawing machine, cutting, fracture mechanics, fracture toughness, modelling, orthotropic material, sawing process, wood.Abstract
In the classical approach, cutting forces and cutting power in sawing processes of orthotropic materials such as wood are generally calculated on the basis of the specific cutting resistance kc (cutting force per unit area of cut). For every type of sawing kinematics (frame saws, band saws and circular sawing machines) different empirical values of specific cutting resistance kc have to be applied. It should be emphasised that sources in the scientific literature and handbooks do not provide any information about wood provenance, nor about cutting conditions in which cutting resistance had been determined. In analyses of sawing processes in which the offcut is formed by shear, Atkins’s ideas that all cutting forms a branch of elastoplastic fracture mechanics can be applied. Thanks to this modern approach it was possible to reveal, using experimental results data of fracture toughness and shear yield stresses of Polish pine (Pinus sylvestris), the significant effect of the raw material provenance (source of wood) on cutting power. In the common model for circular sawing machine kinematics, which is similar to metal milling, the sum of all uncut chip thicknesses of the all the teeth simultaneously engaged represented the mean uncut chip thickness. In this work predictions of the newly-developed model for the circular sawing machine are presented. In the model, beside uncut chip thicknesses changes, appropriate changes in shear yield stress and toughness with tooth/grain orientation have been taken into account. The conducted analyses have demonstrated that values of RMS of cutting power obtained with the new developed model are slightly larger than experimental values. On the other hand computed values of cutting power with the use of the mean uncut chip thicknesses in the model are a bit lower from the empirical one.Downloads
References
Altintas, Y. 2000. Modeling approaches and software for predicting the performance of milling operations at MAL- UBC. Machining Science and Technology 4(3):445-478.
Ammar, A.A.; Bouaziz, Z.: Aghal, A. 2009. Modelling and simulation of the cutting forces for 2.5D pockets machining. Advances in Production Engineering & Management 4(4):163-176.
Atkins, A.G. 2003. Modelling metal cutting using modern ductile fracture mechanics: quantitative explanations for some longstanding problems. Int J Mech Sci 45:373-396.
Atkins, A.G. 2005. Toughness and cutting: A new way of simultaneously determining ductile fracture toughness and strength. Eng Fracture Mech 72:849-860.
Atkins, A.G. 2009. The science and engineering of cutting. The mechanics and process of separating, scratching and puncturing biomaterials, metals and non-metals. Butterworth-Heinemann is an imprint of Elsevier, Oxford.
Atkins, A.G. 2016. Slice-push, formation of grooves and the scale effect in cutting. Interface Focus 6(3): DOI: 10.1098/rsfs.2016.0019
Astakhov, V.P. 2010. Chapter 2: Basic Definitions and Cutting Tool Geometry, Single Point Cutting Tools. In: Geometry of Single-point Turning Tools and Drills. Fundamentals and Practical Applications. [on line] Springer Series in Advanced Manufacturing. Springer London. pp. 54-101. <http://link.springer.com/chapter/10.1007%2F978-1-84996-053-3_2> [accessed December 9, 2016]
Beljo-Lučić, R.; Goglia, V.; Pervan, S.; Dukić, I.; Risović, S. 2004. The influence of wood moisture content on the process of circular rip sawing. Part I: Power requirements and specific cutting forces. Wood Res 49(1):41-49.
Blackman, B.R.K.; Hoult, T.R.; Patel, Y.; Williams, J.G. 2013. Tool sharpness as a factor in machining tests to determine toughness. Eng Fracture Mech 101(2013):47-58.
Böllinghaus, T.; Byrne, G.; Cherpakov, B.I.; Chlebus, E.; Cross, C.E.; Denkena, B.; Dilthey, U.; Hatsuzawa, T.; Herfurth, K.; Herold, H. 2009. Manufacturing engineering. In: Springer Handbook of Mechanical Engineering, K.-H. Grote and E. K. Antonsson (eds.), Springer, Würzburg, pp. 609-656. DOI: 10.1007/978-3-540-30738-9_7
Budak, E. 2006. Analytical models for high performance milling. Part I: Cutting forces, structural deformations and tolerance integrity. Int J Mach Tools & Manuf 46(12-13):1478-1488.
Chuchała, D.; Orlowski, K.A. 2016. Shear yield stresses and fracture toughness of Scots pine (Pinus sylvestris L.) according to the raw material provenance. Chip and Chipless Woodworking processes 10(1): 49-55 <http://www.tuzvo.sk/files/DF/katedry_df/kod/konferencia/2016/chuchala_orlowski.pdf> [accessed December 13, 2016]
Cristóvão, L.; Ekevad, M.; Grönlund, A. 2013. Industrial sawing of Pinus sylvestris L.: Power consumption. BioRes. 8(4):6044-6053.
Engineering Tool Box. 2014. Three-Phase power equations. [on line] [accessed March 23, 2016]
Gere, J.M. 2004. Mechanics of Materials. Thomson Learning Inc. <http://www.hljp.edu.cn/ attachment/20120820084627006.pdf> [accessed December 9, 2016]
Glass, S.V.; Zelinka, S.L. 2010. Moisture Relations and Physical Properties of Wood (Chapter 4). In: Wood Handbook - Wood as an Engineering Material. [on line] (Centennial Edition). General Technical Report FPL-GTR-190. Madison, WI: U.S. Department of Agriculture, Forest Service, Forest Products Laboratory. 508 p. <http://www.fpl.fs.fed.us/documnts/fplgtr/fpl_gtr190.pdf>
Hellström, L.M.; Biller, S.O.; Edvardsson, S.; Gradin, P. 2013. A theoretical and experimental study of the circular sawing process. Holzforschung 68(3):307-312.
Hlásková, L.; Orlowski, K.A.; Kopecký, Z.; Jedinák, M. 2015. Sawing processes as a way of determining fracture toughness and shear yield stresses of wood. BioRes 10(3):5381-5394.
Kopecký, L.; Hlásková, L.; Orlowski, K. 2014. An innovative approach to prediction energetic effects of wood cutting process with circular-saw blades. Wood Research 59(5):827-834.
Krilek, J.; Kováč, J.; Kučera, M. 2014. Wood crosscutting process analysis for circular saws. BioRes 9(1):1417-1429.
Kretschmann, D.E. 2010. Chapter 5, Mechanical Properties of Wood. In: Wood Handbook, Wood as an Engineering Material. General Technical Report FPL-GTR-190. Madison, WI: U.S. Department of Agriculture, Forest Service, Forest Products Laboratory. Centennial Edition. April 2010, 508 p.
Laternser, R.; Gänser, H.P.; Taenzer, L.; Hartmaier, A. 2003. Chip formation in cellular materials. Transactions of the ASME 125:44-49.
Marchal, R.; Mothe, F.; Denaud, L.E.; Thibaut, B.; Bleron, L. 2009. Cutting forces in wood machining - Basics and applications in industrial processes. A review COST Action E35 2004-2008: Wood machining - Micromechanics and fracture. Holzforschung 63(2):157-167. DOI 10.1515/ HF.2009.014.
Merhar, M.; Bučar, B. 2012. Cutting force variability as a consequence of exchangeable cleavage fracture and compressive breakdown of wood tissue. Wood Sci Technol 46(5):965-977.
Nairn, J.A. 2015. Numerical simulation of orthogonal cutting using the material point method. Eng Fracture Mech 149:262-275.
Nairn, J.A. 2016. Numerical modeling of orthogonal cutting: application to woodworking with a bench plane. Interface Focus 6(3): DOI: 10.1098/rsfs.2015.0110 <http://www.cof.orst.edu/cof/wse/ faculty/Nairn/papers/WoodCutting.pdf> [accessed March 29, 2016]
Markopoulos, A.P. 2013. Cutting mechanics and analytical modelling. In: Finite Element Method in Machining Processes. Springer, London, UK, pp. 11-27. DOI: 10.1007/978-1-4471-4330-7_2
Mohammadpanah, A.; Hutton, S.G. 2016a. Dynamics behavior of a guided spline spinning disk, subjected to conservative in-plane edge loads, analytical and experimental investigation. J Vib Acoust 138(4):041005-041005-11. DOI: 10.1115/1.4033456.
Mohammadpanah, A.; Hutton, S.G. 2016b. Modeling and experimental verification of idling and cutting of guided spline circular saws. Global Journal of Researches in Engineering: A Mechanical and Mechanics Engineering 16(2):16p.
Orlicz, T. 1988. Obróbka drewna narzędziami tnącymi. (In Polish: Wood machining with cutting tools) Skrypty SGGW-AR w Warszawie, Wydawnictwo SGGW-AR, Warszawa.
Orlowski, K.A.; Ochrymiuk, T. 2013. Revisiting the determination of cutting power while sawing of wood with circular saw blades by means of fracture mechanics. In: Proceedings of the 21st International Wood Machining Seminar, August 4-7, 2011, Tsukuba, Japan. Eds. IWMS-21 Organizing Committee, The Japan Wood Research Society, pp. 46-55.
Orlowski, K.A.; Ochrymiuk, T.; Atkins, A.; Chuchala, D. 2013. Application of fracture mechanics for energetic effects predictions while wood sawing. Wood Sci Technol 47(5):949-963.
Orlowski, K.A.; Ochrymiuk, T.; Atkins, A. 2014. An innovative approach to the forecasting of energetic effects while wood sawing. Drvna Industrija 65(4):273-281.
Orlowski, K.; Ochrymiuk, T.; Sandak, J.; Sandak, A.; Riggio, M. 2015. Sawing process as a new alternative way of determining some wood properties. In: Proceedings of the 22nd International Wood Machining Seminar /Volume 1/ ed. Hernandez R., Caceres C.B. Quebec City: Centre de Recherche sur les Materiaux Renouvelables Universite Laval, pp. 46-56.
Orlowski, K.A.; Palubicki, B. 2009. Recent progress in research on the cutting processes of wood. A review. COST Action E35 2004-2008: Wood machining - Micromechanics and fracture. Holzforschung 63(2):181-185. DOI 10.1515/HF.2009.015.
Otto, A.; Parmigiani, J. 2015. Velocity, depth-of-cut, and physical property effects on saw chain cutting. BioRes 10(4):7273-7291.
Pantea, R.C. 1999. Wood cutting system: modelling and process simulation. Mémoire présen té à la Faculté des études supérieures de l’université Laval pour l’obtention du grade de maître ès science (M.Sc.). Département de génie mécanique Faculté Des Sciences Et De Genie, Université Laval, (National Library of Canada).
Porankiewicz, B.; Goli, G. 2014. Cutting forces by Oak and Douglas fir machining. Maderas- Cienc Tecnol 16(2):199-216.
Wang, H.; Chang, L.; Ye, L.; Williams, J.G. 2013. Micro-cutting tests: a new way to measure the fracture toughness and yield stress of polymeric nanocomposites. In: Proceedings of the 13th International Conference on Fracture, June 16–21, 2013, Beijing, China <http://www.gruppofrattura.it/ ocs/index.php/ICF/icf13/paper/viewFile/11399/10778>[accessed 20 March 2016]
Williams, J.G.; Patel, Y.; Blackman, B.R.K. 2010. A fracture mechanics analysis of cutting and machining. Eng Fracture Mech 77:293-308.
Williams, J.G.; Patel, Y. 2016. Fundamentals of cutting. Interface Focus 6(3): June 2016. DOI: 10.1098/rsfs.2015.0108
Wyeth, D.J.; Atkins, A.G. 2009. Mixed mode fracture toughness as a separation parameter when cutting polymers. Eng Fracture Mech 76:2690-2697.
Wyeth, D.J.; Goli, G.; Atkins, A.G. 2009. Fracture toughness, chip types and the mechanics of cutting wood. A review: COST Action E35 2004-2008: Wood machining - Micromechanics and fracture. Holzforschung 63. DOI 10.1515/HF.2009.017
