Mechanics and Dynamics of Multifunctional Tools

2015 ◽  
Vol 137 (1) ◽  
Author(s):  
Min Wan ◽  
Zekai Murat Kilic ◽  
Yusuf Altintas
Keyword(s):  
Time Domain ◽  
Prediction Models ◽  
Chip Thickness ◽  
Combined Processes ◽  
Multiple Delays ◽  
Stability Prediction ◽  
Chatter Stability ◽  
Regenerative Effect ◽  
Hole Making ◽  
Chatter Stability Prediction

The mechanics and dynamics of the combined processes are presented for multifunctional tools, which can drill, bore, and chamfer holes in one operation. The oblique cutting forces on each cutting edge with varying geometry are modeled first, followed by their transformations to tangential, radial, and axial directions of the cutter. The regenerative effect of lateral and torsional/axial vibrations is considered in predicting the dynamic chip thickness with multiple delays due to distribution of cutting edges on the cutter body. The lateral and torsional/axial chatter stability of the complete hole making operation is predicted in semidiscrete time domain. The proposed static cutting force and chatter stability prediction models are experimentally proven for two different multifunctional tools in drilling Aluminum Al7050 and Steel AISI1045.

Chatter stability prediction of milling considering nonlinearities

2020 ◽  
pp. 095440542097107
Author(s):  
Yiqing Yang ◽  
Donghui Wu ◽  
Qiang Liu
Keyword(s):  
Cutting Force ◽  
Time Domain ◽  
Cutting Speed ◽  
Dissipated Energy ◽  
Stability Prediction ◽  
Chatter Stability ◽  
Process Damping ◽  
Stability Lobes ◽  
The Time Domain ◽  
Chatter Stability Prediction

Nonlinearities have been evidenced during the chatter vibration of milling. Machinability of the thin-walled part is feed rate and position-dependent, and is subject to process damping at low cutting speed. Therefore, chatter stability prediction of milling considering nonlinear cutting force, nonlinear structural stiffness and process damping is investigated. The cutting force and stiffness are established based on the polynomial model and the process damping is investigated based on the dissipated energy. The dynamic cutting force and stability lobes are solved in the time domain with coefficients updated at each iteration. By formulating the displacement as an expanded form via the perturbation method, the time-consuming solution of delay differential equations is avoided. After formulating the identification of the nonlinear model via cutting tests and modal tests, numerical simulations considering nonlinearities are carried out and compared with the analytical method. The proposed method attains high accuracy of classic time-domain solution, but with an improved computational efficiency. Finally, cutting tests are conducted to verify the prediction of cutting force and stability lobes.

scholarly journals Mechanics and Dynamics of Serrated End Mills

Manufacturing ◽  
2002 ◽  
Author(s):  
S. Doruk Merdol ◽  
Yusuf Altintas
Keyword(s):  
Time Domain ◽  
Cutting Forces ◽  
Chip Thickness ◽  
Cutting Edge ◽  
Chatter Stability ◽  
Edge Point ◽  
Oblique Cutting ◽  
Edge Geometry ◽  
End Mills ◽  
Chatter Stability Lobes

Mechanics and dynamics of serrated milling cutters are presented in the article. The serrated flute design knots are fitted to a cubic spline, which is then projected on helical flutes. Cutting edge geometry at any point along the serrated flute is represented by its immersion angle and tangent vectors in radial, tangential and helix directions. The chip thickness removed by each cutting edge point is determined by using previously proposed exact kinematics of dynamic milling. The cutting forces are evaluated by orthogonal to oblique cutting mechanics transformation. The experimentally proven model is able to predict the cutting forces and chatter stability lobes in time domain.

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