Specific cutting force coefficients modeling of end milling by neural network

2000 ◽  
Vol 14 (6) ◽  
pp. 622-632 ◽  
Author(s):  
Sin-Young Lee ◽  
Jang Moo Lee
Author(s):  
Han Ul Lee ◽  
Dong-Woo Cho ◽  
Kornel F. Ehmann

Complex three-dimensional miniature components are needed in a wide range of industrial applications from aerospace to biomedicine. Such products can be effectively produced by micro-end-milling processes that are capable of accurately producing high aspect ratio features and parts. This paper presents a mechanistic cutting force model for the precise prediction of the cutting forces in micro-end-milling under various cutting conditions. In order to account for the actual physical phenomena at the edge of the tool, the components of the cutting force vector are determined based on the newly introduced concept of the partial effective rake angle. The proposed model also uses instantaneous cutting force coefficients that are independent of the end-milling cutting conditions. These cutting force coefficients, determined from measured cutting forces, reflect the influence of the majority of cutting mechanisms involved in micro-end-milling including the minimum chip-thickness effect. The comparison of the predicted and measured cutting forces has shown that the proposed method provides very accurate results.


Author(s):  
Kaining Shi ◽  
Ning Liu ◽  
Sibao Wang ◽  
Chi Ma ◽  
Bo Yang ◽  
...  

Abstract Cutting force is a very important factor in machining processes for predicting chatter, surface roughness and machining efficiency. For a given cutter, cutting force is determined by cutting force coefficients and uncut chip thickness. Once a new cutter is adopted, repeated experiments are carried out to calibrate its cutting force coefficients. To reduce the high cost and longtime experiments, theoretical analysis of the effect of cutter parameters on cutting force is required. In current literatures, some cutter parameters, such as helix angle and pitch angle, have been studied to explore their effects on cutting force. However, there is little research about the effect of teeth number on the cutting force. To fill up this gap, the effect of teeth number on cutting force is studied in the paper. Firstly, it is derived and experimentally verified that the cutting force coefficients are unchanged for cutters with different teeth number but the same teeth parameters, e.g., rake angle, shear angle, etc. Secondly, by matching the measured cutting force point with the cutter rotation angle, the cutting force coefficients can be calibrated by only one experiment when we assume that the material of the cutter is the same. Therefore, the cutting forces generated by cutters with different teeth numbers can be predicted based on only one experiment. Thirdly, from the various comparisons, it is concluded that cutter with 2 teeth number is suggested for side milling and cutter with 3 teeth number is suggested for slotting when surface roughness is considered. The cutter with 5 teeth number is suggested when only the machining efficiency is concerned. Finally, various experiments are carried out to verify the proposed study in milling of titanium alloy Ti6Al4V (TC4), and the comparison results show a good agreement.


2019 ◽  
Vol 13 (3) ◽  
pp. 232-240
Author(s):  
Zhixin Feng ◽  
Meng Liu ◽  
Guohe Li

Background: Calibration of cutting coefficients is the key content in modeling a mechanistic cutting force model. Generally, in modeling cutting force for ball end milling, the tangent, radial and binormal cutting force coefficients are each considered as a polynomial, respectively. This fact is due to the dependency between the cutting force coefficients and the cutting edge inclination angle which is variable in ball-end mills. Objective: This paper presents an approach to determine the polynomial cutting force coefficients. Methods: In this approach, the cutting force coefficients are expressed as explicit linear equations about the average slotting forces. After analysis of the least square regression method which is utilized in the cutting coefficients evaluation, the principle of cutting parameters choice in calibration experiment and the relationship between the order of polynomial and the number of experiments are presented. Besides, a lot of patents on identification of polynomial cutting coefficients for milling force model were studied. Results: Finally, a series of semi-slotting verification cutting tests were arranged, the measured force agrees well with the predicted force, which demonstrates the effectiveness of this approach. Conclusion: Based on the calibration method proposed in this paper, the cutting coefficients can be determined through (m+2) slotting experiments for m-degree shearing coefficients polynomial theoretically.


2005 ◽  
Vol 127 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Jeong Hoon Ko ◽  
Dong-Woo Cho

Application of a ball-end milling process model to a CAD/CAM or CAPP system requires a generalized methodology to determine the cutting force coefficients for different cutting conditions. In this paper, we propose a mechanistic cutting force model for 3D ball-end milling using instantaneous cutting force coefficients that are independent of the cutting conditions. The uncut chip thickness model for three-dimensional machining considers cutter deflection and runout. An in-depth analysis of the characteristics of these cutting force coefficients, which can be determined from only a few test cuts, is provided. For more accurate cutting force predictions, the size effect is also modeled using the cutter edge length of the ball-end mill and is incorporated into the cutting force model. This method of estimating the 3D ball-end milling force coefficients has been tested experimentally for various cutting conditions.


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