Study of the Classification of Cutting Forces and the Build of Accurate Milling Force Model in End Milling

2006 ◽  
Vol 532-533 ◽  
pp. 636-639
Author(s):  
Yong Gang Kang ◽  
Zhong Qi Wang ◽  
Wen Ming Lou ◽  
Cheng Yu Jiang

A new approach is proposed to model the milling force based on the cutting force shape characteristics in end milling. The relationship between the cutting force shape characteristics and the cutting depths is analyzed and milling forces are classified into 10 types according to the combination of cutting depths. Further, force indices are extracted and then the real cutting depths are detected based on the changes of force curve characteristics via the force indices in end milling process. Then, bring forward a method of modeling cutting force based on the different types, and the use of real cutting depth makes the model to be more accurately. More important, experiments designed on the classification of milling forces strengthen the pertinence, and makes the experiment data more reliable. The approach is validated through experiments on aluminum alloy 7050-T7451.

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.


2021 ◽  
Vol 34 (1) ◽  
Author(s):  
Zhenjing Duan ◽  
Changhe Li ◽  
Wenfeng Ding ◽  
Yanbin Zhang ◽  
Min Yang ◽  
...  

AbstractAluminum alloy is the main structural material of aircraft, launch vehicle, spaceship, and space station and is processed by milling. However, tool wear and vibration are the bottlenecks in the milling process of aviation aluminum alloy. The machining accuracy and surface quality of aluminum alloy milling depend on the cutting parameters, material mechanical properties, machine tools, and other parameters. In particular, milling force is the crucial factor to determine material removal and workpiece surface integrity. However, establishing the prediction model of milling force is important and difficult because milling force is the result of multiparameter coupling of process system. The research progress of cutting force model is reviewed from three modeling methods: empirical model, finite element simulation, and instantaneous milling force model. The problems of cutting force modeling are also determined. In view of these problems, the future work direction is proposed in the following four aspects: (1) high-speed milling is adopted for the thin-walled structure of large aviation with large cutting depth, which easily produces high residual stress. The residual stress should be analyzed under this particular condition. (2) Multiple factors (e.g., eccentric swing milling parameters, lubrication conditions, tools, tool and workpiece deformation, and size effect) should be considered comprehensively when modeling instantaneous milling forces, especially for micro milling and complex surface machining. (3) The database of milling force model, including the corresponding workpiece materials, working condition, cutting tools (geometric figures and coatings), and other parameters, should be established. (4) The effect of chatter on the prediction accuracy of milling force cannot be ignored in thin-walled workpiece milling. (5) The cutting force of aviation aluminum alloy milling under the condition of minimum quantity lubrication (mql) and nanofluid mql should be predicted.


Author(s):  
Xiaohong Lu ◽  
Hua Wang ◽  
Zhenyuan Jia ◽  
Yixuan Feng ◽  
Steven Y Liang

Micro-milling forces, cutting temperature, and thermal–mechanical coupling are the key research topics about the mechanism of micro-milling nickel-based superalloy Inconel 718. Most current analyses of thermal–mechanical coupling in micro-milling are based on finite element or experimental methods. The simulation is not conducive to revealing the micro-milling mechanism, while the results of experiments are only valid for certain machine tool and workpiece material. Few analytical coupling models of cutting force and cutting temperature during micro-milling process have been proposed. Therefore, the authors studied coupled thermal–mechanical analyses of micro-milling Inconel 718 and presented a revised three-dimensional analytical model of micro-milling forces, which considers the effects of the cutting temperature and the ploughing force caused by the arc of cutting edge during shear-dominant cutting process. Then, an analytical cutting temperature model based on Fourier’s law is presented by regarding the contact area as a moving finite-length heat source. Coupling calculation between micro-milling force model and temperature model through an iterative process is conducted. The novelty is including cutting temperature into micro-milling force model, which simulates the interaction between cutting force and cutting temperature during micro-milling process. The established model predicts both micro-milling force and temperature. Finally, experiments are conducted to verify the accuracy of the proposed analytical method. Based on the coupled thermal–mechanical analyses and experimental results, the authors reveal the effects of cutting parameters on micro-milling forces and temperature.


2020 ◽  
pp. 073168442097176
Author(s):  
Fuji Wang ◽  
Guangjian Bi ◽  
Fuda Ning

The milling process is always required to achieve dimensional tolerance for the near-net-shape carbon fiber reinforced polymer (CFRP) parts. However, delamination and cracking are inevitably induced in milling CFRP due to the excessive milling forces. The milling forces should be thereby well controlled to reduce damages of CFRP parts. Developing a theoretical milling force model is an effective approach to understand the mechanism of milling force generation. Recent studies have established the predictive models; however, the interlaminar effect impacting the material removal process is not considered during milling multidirectional CFRP laminate, limiting the predictive model accuracy. In this work, a model of dynamic milling force for multidirectional CFRP laminate was developed by considering the interlaminar effect for the first time. The specific cutting energy predicted by the artificial neural network methodology was employed to calculate the milling forces during milling a single CFRP layer. Meantime, the support of the layer was enhanced due to the interlaminar effect, and the correction coefficients for each type of support were proposed to reflect the role of this effect. Then, the overall milling forces for multidirectional CFRP laminate can be obtained via the superposition principle, which agreed well with the experimentally measured results.


2018 ◽  
Vol 10 (9) ◽  
pp. 168781401879818 ◽  
Author(s):  
Xianglei Zhang ◽  
Jing Zhang ◽  
Hongming Zhou ◽  
Yan Ren ◽  
Mingming Xu

A novel milling force model for cutting aviation aluminum alloy 7075 using carbide end mill is established in this article. A two-dimensional end-milling model is set up to investigate the influence of tool geometric parameters on milling force with the single-factor analysis. The relationship between milling forces and tool geometric parameters is obtained by nonlinear regression fitting method. Based on the existing empirical model of milling force, quadratic polynomial factor is taken into consideration to explore the influence of tool geometric parameters on milling force. Thus, a novel milling force model is built up which includes tool geometric parameters and milling parameters. The coefficients of the novel model are identified by the direct method and the loop method. The precisions of the coefficients obtained by the two methods are compared between prediction values and experiment values. After comparison, the model whose coefficients are obtained by loop method has higher prediction ability. End-milling experiments were carried out to verify the prediction accuracy of the novel milling force model. The result shows that the novel model of milling force has high accuracy in prediction. The method of building the milling force model proposed in this article can be applied to other types of milling cutter.


2021 ◽  
Author(s):  
Haiyan Wang ◽  
Kexin Tao ◽  
Tian Jin

Abstract Milling forces play an important role in the milling process and are generally calculated by the mechanistic or numerical methods, reliable model of cutting force is very important for the simulation of milling process, which has big scientific significance to further improve machining quality. Ball helical milling technology is used to make holes based on the cutting principle of helical milling using ball end cutter, due to the influence of spherical surface machining characteristic, the modeling of cutting force in ball helical milling is difficult. Therefore, the main purpose of this paper is to first establish an analytical cutting force model in the ball helical milling process. Considering cutting characteristics in the axial feed, the kinematics of ball helical milling is first presented, then the chip thickness distribution in different directions along the cutting edges are predicted. Furthermore, based on the characteristics of helical milling technology and geometry shape of ball end mill and the classical mechanical cutting force model, through the study on the ball-end milling mechanics, a new relatively accurate theoretical cutting force model is established. At the same time, cutting force coefficients are identified through instantaneous force method according to the Ti-alloy experimental research result. Finally, higher simulation precision of cutting force model in ball helical milling process is received.


2021 ◽  
Author(s):  
Ce Zhang ◽  
Changyou LI ◽  
Mengtao Xu ◽  
Guo Yao ◽  
Zhendong Liu ◽  
...  

Abstract Ball-end milling cutters are one of the most widely used cutters in the automotive, aerospace, die and machine parts industries. In addition, milling chatter will reduce the surface quality and production efficiency, resulting in noise. It is particularly important to model the cutting force and analyze the flutter stability of ball-end milling cutters. In this paper, a simplified milling force model of ball-end milling cutter with three degrees of freedom was established based on Merchant bevel cutting theory. The model simplified the milling force coefficient. The expressions of instantaneous milling area considering the vibration displacements in X, Y and Z directions were derived. The nonlinear dynamic cutting force model of ball-end milling cutter with three degrees of freedom was established. The nonlinear chatter vibration mechanical model of ball-end milling cutter with three degrees of freedom was established by introducing the time delay term, the stability analysis is carried out by time domain simulation. The proposed models were experimentally verified.


2011 ◽  
Vol 121-126 ◽  
pp. 2098-2104
Author(s):  
Xiu Lin Sui ◽  
Ping Zhang

In this paper, influence mechanism of variously physical factors for milling force in any feed direction is studied during the milling process. Firstly, the effects of spindle eccentricity, cutter deflection and cutter vibration for the instantaneously undeformed cutting thickness are analyzed, and the mathematical expressions of chip thickness is set up. Then,on this basis of cutting force and chip load, the milling force model of ball-end mill with considering integrated physical factors is established though the differential method, and a simulation system for prediction of milling forces during the milling process is developed. This milling force model is verified through simulation and analysis of milling forces.


2018 ◽  
Vol 764 ◽  
pp. 399-407
Author(s):  
Yue Zhang ◽  
Zhi Qiang Yu ◽  
Tai Yong Wang

The instantaneous uncut chip thickness is an important parameter in the study of milling force model. By analyzing the real tooth trajectory in milling process, accurate instantaneous uncut chip thickness can be obtained to solve the complex transcendental equation. Traditional chip thickness models always simplify the tooth trajectory to get approximate solution. A new instantaneous uncut chip thickness model is proposed in this paper. Based on real tooth trajectory of general end milling cutter, a Taylor's series is used to approximate the involved infinitesimal variable in the transcendental equation, which results in an explicit expression for practical application of the uncut chip thickness with higher accuracy compared to the traditional model.


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