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.

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.

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.

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.

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.

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.

Analysis of Cutting Force in Elastomer End-Milling

2017 ◽  
Vol 11 (6) ◽  
pp. 958-963
Author(s):  
Koji Teramoto ◽  
◽  
Takahiro Kunishima ◽  
Hiroki Matsumoto
Keyword(s):  
Parameter Identification ◽  
Cutting Force ◽  
Cutting Forces ◽  
End Milling ◽  
Process Models ◽  
Force Model ◽  
Cutting Force Model ◽  
Cutting Force Prediction ◽  
Force Prediction ◽  
The Stability

Elastomer end-milling is attracting attention for its role in the small-lot production of elastomeric parts. In order to apply end-milling to the production of elastomeric parts, it is important that the workpiece be held stably to avoid deformation. To evaluate the stability of workholding, it is necessary to predict cutting forces in elastomer end-milling. Cutting force prediction for metal workpiece end-milling has been investigated for many years, and many process models for end-milling have been proposed. However, the applicability of these models to elastomer end-milling has not been discussed. In this paper, the characteristics of the cutting force in elastomer end-milling are evaluated experimentally. A standard cutting force model and its parameter identification method are introduced. By using this cutting force model, measured cutting forces are compared against the calculated results. The comparison makes it clear that the standard cutting force model for metal end-milling can be applied to down milling for a rough evaluation.

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.

Accurate Milling Process Simulation Using ME Z-Map Model

Manufacturing ◽  
2003 ◽  
Author(s):  
Han Ul Lee ◽  
Dong-Woo Cho
Keyword(s):  
Cutting Force ◽  
Process Simulation ◽  
Cutting Forces ◽  
Computing Time ◽  
Milling Process ◽  
Simulation System ◽  
Grid Size ◽  
Force Model ◽  
Cutting Force Model ◽  
Edge Node

In this paper, a milling process simulation system was constructed and ME Z-map (Moving Edge node Z-map) model was developed to elevate the performance of this system. The milling process simulation system computes the cutting configuration and then the cutting forces are predicted using these calculated configurations. In this system, an improved cutting force model which is independent of cutting conditions is used to more precisely predict the cutting forces. In the process, the ME Z-map model was used for more accurate computing of cutting configuration. Due to the edge node, ME Z-map model produces more accurate cutting configuration than the conventional Z-map models even with five to ten times larger grid size, which reduces the computing time dramatically. The superiority of the ME Z-map model was confirmed through comparison with the conventional Z-map.

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