scholarly journals VALIDATION OF CUTTING FORCE CHARACTERISTIC FOR COMPLEX TOOLPATH

2016 ◽  
Vol 3 ◽  
pp. 78-81
Author(s):  
Henrik Tamás Sykora ◽  
Attila Kovács ◽  
Dániel Bachrathy
Keyword(s):  
Cutting Force ◽  
Tool Path ◽  
Removal Rate ◽  
Chip Thickness ◽  
Simulation Method ◽  
Milling Process ◽  
Simulation Software ◽  
Force Characteristic ◽  
Force Model ◽  
Force Data

In the design phase of the milling process, there is a great need for the prediction of the cutting force, the required torque and power of the spindle. These informations could be used to optimize the tool path and improve the material removal rate. In this work, we present our dexel based simulation software, its modules, calculations steps and the simulation method. Different force models were analysed to describe the specific force as a function of the local chip thickness. The models were fitted to the measured force data. Then the selected force model was validated in case of a complex tool path.

Off-line error compensation in corner milling process

2016 ◽  
Vol 232 (7) ◽  
pp. 1172-1181 ◽  
Author(s):  
Caixu Yue ◽  
Xianli Liu ◽  
Yunpeng Ding ◽  
Steven Y Liang
Keyword(s):  
Cutting Force ◽  
Error Compensation ◽  
Tool Path ◽  
Chip Thickness ◽  
Milling Process ◽  
Process Conditions ◽  
Force Model ◽  
Tool Deflection ◽  
Profile Error ◽  
Compensation Algorithm

Tool deflection induced by cutting force could result in dimensional inaccuracies or profile error in corner milling process. Error compensation has been proved to be an effective method to get accuracy component in milling process. This article presents a methodology to compensate profile errors by modifying tool path. The compensation effect strongly depends on accuracy of the cutting force model used. The mathematical expression of chip thickness is proposed based on the true track of cutting edge for corner milling process, which considers the effect of tool deflection. The deflection of tool is calculated by finite element method. Then, an off-line compensation algorithm for corner profile error is developed. Following the theoretical analysis, the effect of the error compensation algorithm is verified by experimental study. The outcome provides useful comprehension about selection of process conditions for corner milling process.

An Improved Tool Path Model Including Periodic Delay for Chatter Prediction in Milling

2006 ◽  
Vol 2 (2) ◽  
pp. 167-179 ◽  
Author(s):  
R. P. H. Faassen ◽  
N. van de Wouw ◽  
H. Nijmeijer ◽  
J. A. J. Oosterling
Keyword(s):  
Periodic Solution ◽  
Cutting Force ◽  
Tool Path ◽  
Chip Thickness ◽  
Milling Process ◽  
Path Model ◽  
Force Model ◽  
Cutting Force Model ◽  
Periodic Delay ◽  
The Stability

The efficiency of the high-speed milling process is often limited by the occurrence of chatter. In order to predict the occurrence of chatter, accurate models are necessary. In most models regarding milling, the cutter is assumed to follow a circular tooth path. However, the real tool path is trochoidal in the ideal case, i.e., without vibrations of the tool. Therefore, models using a circular tool path lead to errors, especially when the cutting angle is close to 0 or π radians. An updated model for the milling process is presented which features a model of the undeformed chip thickness and a time-periodic delay. In combination with this tool path model, a nonlinear cutting force model is used, to include the dependency of the chatter boundary on the feed rate. The stability of the milling system, and hence the occurrence of chatter, is investigated using both the traditional and the trochoidal model by means of the semi-discretization method. Due to the combination of this updated tool path model with a nonlinear cutting force model, the periodic solution of this system, representing a chatter-free process, needs to be computed before the stability can be investigated. This periodic solution is computed using a finite difference method for delay-differential equations. Especially for low immersion cuts, the stability lobes diagram (SLD) using the updated model shows significant differences compared to the SLD using the traditional model. Also the use of the nonlinear cutting force model results in significant differences in the SLD compared to the linear cutting force model.

Dynamic cutting force prediction for micro end milling considering tool vibrations and run-out

2018 ◽  
Vol 233 (7) ◽  
pp. 2248-2261 ◽  
Author(s):  
Xuewei Zhang ◽  
Tianbiao Yu ◽  
Wanshan Wang
Keyword(s):  
Cutting Force ◽  
Cutting Forces ◽  
End Milling ◽  
Chip Thickness ◽  
Milling Process ◽  
Force Model ◽  
Dynamic Cutting Force ◽  
Micro End Milling ◽  
Tool Vibrations ◽  
End Milling Process

An accurate prediction of cutting forces in the micro end milling, which is affected by many factors, is the basis for increasing the machining productivity and selecting optimal cutting parameters. This paper develops a dynamic cutting force model in the micro end milling taking into account tool vibrations and run-out. The influence of tool run-out is integrated with the trochoidal trajectory of tooth and the size effect of cutting edge radius into the static undeformed chip thickness. Meanwhile, the real-time tool vibrations are obtained from differential motion equations with the measured modal parameters, in which the process damping effect is superposed as feedback on the undeformed chip thickness. The proposed dynamic cutting force model has been experimentally validated in the micro end milling process of the Al6061 workpiece. The tool run-out parameters and cutting forces coefficients can be identified on the basis of the measured cutting forces. Compared with the traditional model without tool vibrations and run-out, the predicted and measured cutting forces in the micro end milling process show closer agreement when considering tool vibrations and run-out.

A Mechanistic Cutting Force Model for 3D Ball-end Milling

2000 ◽  
Vol 123 (1) ◽  
pp. 23-29 ◽  
Author(s):  
Hsi-Yung Feng ◽  
Ning Su
Keyword(s):  
Cutting Force ◽  
Cutting Forces ◽  
End Milling ◽  
Chip Thickness ◽  
Milling Process ◽  
Force Model ◽  
Cutting Force Model ◽  
Ball End Milling ◽  
End Milling Process ◽  
Force Relationship

This paper presents an improved mechanistic cutting force model for the ball-end milling process. The objective is to accurately model the cutting forces for nonhorizontal and cross-feed cutter movements in 3D finishing ball-end milling. Main features of the model include: (1) a robust cut geometry identification method to establish the complicated engaged area on the cutter; (2) a generalized algorithm to determine the undeformed chip thickness for each engaged cutting edge element; and (3) a comprehensive empirical chip-force relationship to characterize nonhorizontal cutting mechanics. Experimental results have shown that the present model gives excellent predictions of cutting forces in 3D ball-end milling.

An Improved Tool Path Model Including Gyroscopic Effect for Instantaneous Cutting Force Prediction in High-Speed Milling

2011 ◽  
Vol 418-420 ◽  
pp. 840-843
Author(s):  
Qing Hua Song ◽  
Xing Ai
Keyword(s):  
Cutting Force ◽  
High Speed ◽  
Tool Path ◽  
Milling Process ◽  
Path Model ◽  
Force Model ◽  
Cutting Force Model ◽  
Gyroscopic Effect ◽  
Cutting Force Prediction ◽  
High Speed Milling

The efficiency of the high-speed milling process is often limited by the occurrence of chatter. In order to predict the occurrence of chatter, accurate models are necessary. With the speed increasing, gyroscopic effect plays an important pole on the system behavior, including dynamic characteristic and rotating behavior. Considering the influence of gyroscopic effect on rotating behavior, an updated model for the milling process is presented which features as model of the equivalent profile of tool. In combination with this model, a nonlinear instantaneous cutting force model is proposed. The use of this updated equivalent profile of tool results in significant differences in the static uncut thickness compared to the traditional model.

scholarly journals Modeling and experimental verification of the dead metal zone for cutting force prediction in micro milling

2021 ◽  
Author(s):  
Bowen Song ◽  
xiubing jing ◽  
Jian Xu ◽  
Fujun Wang ◽  
Huaizhong Li
Keyword(s):  
Cutting Force ◽  
Metal Cutting ◽  
Chip Thickness ◽  
Simulation Software ◽  
Separation Point ◽  
Micro Milling ◽  
Force Model ◽  
Cutting Force Prediction ◽  
Dead Metal Zone ◽  
The Dead

Abstract In micro-cutting process, ploughing phenomenon occurring due to the dead metal zone (DMZ) leads to substantial ploughing force resulting in an obvious contribution to the total cutting force. To improve accuracy of the cutting force predicted, this paper aimed to explore the DMZ geometry related to the cutting depth and tool edge radius and thereof effect on cutting force. The prominent contribution of this research is to establish a new DMZ model by employing the slip-line field theory of the plastic formation. Based on the proposed model, DMZ are divided into shearing-dominated, mixed shearing and ploughing, and pure ploughing according to the minimum uncut chip thickness (MUCT). It is firstly proposed that the inner vertex of DMZ is the separation point of shearing effect and ploughing effect during metal cutting. The shape of the DMZ is theoretically calculated by an analytical way and verified by the simulation software. Finally, a cutting force model including shear force and ploughing force is established and verified by a series of experiments. The predicted cutting forces show remarkable agreement with those measured. The result proves that the separation point model is correct and can effectively demonstrate the ploughing force to accurately predict cutting force.

scholarly journals Modeling and Estimation of Cutting Forces in Ball Helical Milling Process

2021 ◽  
Author(s):  
Haiyan Wang ◽  
Kexin Tao ◽  
Tian Jin
Keyword(s):  
Cutting Force ◽  
End Milling ◽  
Spherical Surface ◽  
Research Result ◽  
Chip Thickness ◽  
Milling Process ◽  
Helical Milling ◽  
Force Model ◽  
Cutting Force Model ◽  
Milling Forces

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.

scholarly journals Prediction of Nonlinear Micro-Milling Force with a Novel Minimum Uncut Chip Thickness Model

Micromachines ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1495
Author(s):  
Tongshun Liu ◽  
Kedong Zhang ◽  
Gang Wang ◽  
Chengdong Wang
Keyword(s):  
Cutting Force ◽  
Chip Thickness ◽  
Micro Milling ◽  
Force Model ◽  
Force Coefficient ◽  
Uncut Chip Thickness ◽  
Milling Force ◽  
Minimum Uncut Chip Thickness ◽  
Cutting Force Coefficient ◽  
Milling Force Model

The minimum uncut chip thickness (MUCT), dividing the cutting zone into the shear region and the ploughing region, has a strong nonlinear effect on the cutting force of micro-milling. Determining the MUCT value is fundamental in order to predict the micro-milling force. In this study, based on the assumption that the normal shear force and the normal ploughing force are equivalent at the MUCT point, a novel analytical MUCT model considering the comprehensive effect of shear stress, friction angle, ploughing coefficient and cutting-edge radius is constructed to determine the MUCT. Nonlinear piecewise cutting force coefficient functions with the novel MUCT as the break point are constructed to represent the distribution of the shear/ploughing force under the effect of the minimum uncut chip thickness. By integrating the cutting force coefficient function, the nonlinear micro-milling force is predicted. Theoretical analysis shows that the nonlinear cutting force coefficient function embedded with the novel MUCT is absolutely integrable, making the micro-milling force model more stable and accurate than the conventional models. Moreover, by considering different factors in the MUCT model, the proposed micro-milling force model is more flexible than the traditional models. Micro-milling experiments under different cutting conditions have verified the efficiency and improvement of the proposed micro-milling force model.

An accurate instantaneous uncut chip thickness model combining runout effect in micro-milling using cutters with the non-uniform helix and pitch angles

2019 ◽  
Vol 234 (5) ◽  
pp. 859-870 ◽  
Author(s):  
Qiang Guo ◽  
Yan Jiang ◽  
Zhibo Yang ◽  
Fei Yan
Keyword(s):  
Tool Path ◽  
Chip Thickness ◽  
Milling Process ◽  
Machining Process ◽  
Micro Milling ◽  
Cutter Runout ◽  
Model Combining ◽  
Key Factor ◽  
Cutting Point ◽  
Instantaneous Uncut Chip Thickness

As a key factor, the accuracy of the instantaneous undeformed thickness model determines the force-predicting precision and further affects workpiece machining precision in the micro-milling process. The runout with five parameters affects the machining process more significantly compared with macro-milling. Furthermore, modern industry uses cutters with non-uniform pitch and helix angles more and more common for their excellent properties. In this article, an instantaneous undeformed thickness model is presented regarding cutter runout, variable pitch, and helix angles in the micro-milling process. The cutter edge with the cutter runout effect is modeled. Then, the intersecting ellipse between the plane vertical to the spindle axis and the cutter surface which is a cylinder can be gained. Based on this, the points, which are used to remove the material, on the ellipse as well as cutter edges are calculated. The true trochoid trajectory for each cutting point along the tool path is built. Finally, the instantaneous undeformed thickness values are computed using a numerical algorithm. In addition, this article analyzes runout parameters’ effects on the instantaneous undeformed thickness values. After that, helix and pitch angles’ effects on the instantaneous undeformed thickness are studied. Ultimately, the last section verifies the correctness and validity of the instantaneous undeformed thickness model based on the experiment conducted in the literature.

scholarly journals A solid-analytical-based model for extracting cutter-workpiece engagement in 5-axis flank machining

2018 ◽  
Vol 237 ◽  
pp. 01009
Author(s):  
Dongdong Li ◽  
Weimin Zhang ◽  
Tengfei Shang ◽  
Tianhong Gao ◽  
Shuo Liu ◽  
...  
Keyword(s):  
Material Removal ◽  
Tool Path ◽  
Removal Rate ◽  
Cutting Tools ◽  
Simulation Method ◽  
Flank Milling ◽  
Milling Force ◽  
3D Space ◽  
High Efficient ◽  
Cam Software

5-axis flank milling is applied extensively in aerospace, die-molds, and automotive industries because of high efficient material removal rate. Commercial CAM software can only simulate the tool path and collision at present, but cannot handle with cutting force during cutting process due to the variable geometrical cutter workpiece engagement (CWE) region of 5-axis milling. This paper presents a novel solid analytical model for extracting the CWE maps. The CWE is obtained analytically by performing Boolean operations between the cutter and in-process-workpiece (IPW) at any given cutter location (CL) point, instead of using the cutter and the removal volume. The proposed process simulation method could identify the CWE efficiently and precisely for general cutting tools. Finally, the CWE boundaries are mapped from a 3D space into a 2D plane defined by the immersion angle and the axial depth of a given cutter. The proposed solution can be easily integrated into the CAM software for predicting milling force and optimizing parameters in 5-axis milling.

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