TY - JOUR
T1 - Cutting forces in fast-/slow tool servo diamond turning of micro-structured surfaces
AU - Zhu, Zhiwei
AU - To, Suet
AU - Zhu, Wu Le
AU - Huang, Peng
AU - Zhou, Xiaoqin
N1 - Funding Information:
This work was jointly supported by the National Natural Science Foundation of China (51705254, 51675455), the Natural Science Foundation of Jiangsu Province (BK20170836), and the Fundamental Research Funds for the Central Universities (30917011301, 309171A8804).
Publisher Copyright:
© 2018 Elsevier Ltd
PY - 2019/1
Y1 - 2019/1
N2 - Although fast-/slow tool servo (F-/STS) diamond turning is widely employed to generate micro-structured surfaces, very limited attention has been focused on the cutting force which directly reflects the material removal behavior in F-/STS. In this study, theoretical analysis on the cutting force is conducted through both finite element and mechanistic analytical models to present a systematic investigation. Based on direct observation from the FE model that the shear angle varies with respect to the auxiliary servo motion, an analytical model is proposed to simultaneously predict the average and variation of the shear angle considering features of the oscillated servo motion. A comprehensive force model is developed for orthogonal cutting with a round-edged cutter, and the depth-of-cut (DoC) dependent shearing and ploughing effects are considered. With the shearing based material removal, dynamic shear strain, shear strain rate, and stress distribution inside the shear band are modeled together with the dynamic equivalent rake angle to derive the material removal force through the slip-line field theory, and the complex interaction between the chip and cutter in the rake face is also investigated to obtain the corresponding frictional force. With the DoC being smaller than the critical chip thickness, the ploughing force is modeled to be proportionate to the interference volume between the cutter and workpiece with full consideration of the dynamic equivalent clearance angle. Finally, the overall cutting force in F-/STS is estimated using the cutter edge discretization method with further experimental demonstration through the slow tool servo diamond turning of a typical micro-structured surface.
AB - Although fast-/slow tool servo (F-/STS) diamond turning is widely employed to generate micro-structured surfaces, very limited attention has been focused on the cutting force which directly reflects the material removal behavior in F-/STS. In this study, theoretical analysis on the cutting force is conducted through both finite element and mechanistic analytical models to present a systematic investigation. Based on direct observation from the FE model that the shear angle varies with respect to the auxiliary servo motion, an analytical model is proposed to simultaneously predict the average and variation of the shear angle considering features of the oscillated servo motion. A comprehensive force model is developed for orthogonal cutting with a round-edged cutter, and the depth-of-cut (DoC) dependent shearing and ploughing effects are considered. With the shearing based material removal, dynamic shear strain, shear strain rate, and stress distribution inside the shear band are modeled together with the dynamic equivalent rake angle to derive the material removal force through the slip-line field theory, and the complex interaction between the chip and cutter in the rake face is also investigated to obtain the corresponding frictional force. With the DoC being smaller than the critical chip thickness, the ploughing force is modeled to be proportionate to the interference volume between the cutter and workpiece with full consideration of the dynamic equivalent clearance angle. Finally, the overall cutting force in F-/STS is estimated using the cutter edge discretization method with further experimental demonstration through the slow tool servo diamond turning of a typical micro-structured surface.
KW - Cutting force
KW - Diamond turning
KW - Fast-/slow tool servo
KW - Mechanistic model
KW - Micro-structured surface
UR - http://www.scopus.com/inward/record.url?scp=85054176360&partnerID=8YFLogxK
U2 - 10.1016/j.ijmachtools.2018.09.003
DO - 10.1016/j.ijmachtools.2018.09.003
M3 - Journal article
AN - SCOPUS:85054176360
SN - 0890-6955
VL - 136
SP - 62
EP - 75
JO - International Journal of Machine Tools and Manufacture
JF - International Journal of Machine Tools and Manufacture
ER -