Stability analysis of milling process by combining the gyroscopic effect with the symmetry and runout of the cutter

2021 ◽  
Vol 161 ◽  
pp. 107977
Author(s):  
Min Wan ◽  
Zi-Yu Dong ◽  
Yun Yang ◽  
Wei-Hong Zhang
Author(s):  
Xiaohong Lu ◽  
Zhenyuan Jia ◽  
Shengqian Liu ◽  
Kun Yang ◽  
Yixuan Feng ◽  
...  

Abstract In the micro-milling process, the minimization of tool chatter is critical for good surface finish quality. The analysis of chatter requires an understanding of the milling tool as well as the dynamics of milling system structure. Frequency response function (FRF) at the micro-milling tool point reflects dynamic behavior of the whole micro-milling machine–spindle–tool system. However, the tool point FRF of micro-milling cannot be obtained directly through the hammering test. To solve the problem, the authors get the FRF of the spindle system based on the rotating Timoshenko beam theory and the receptance coupling substructure analysis (RCSA), and the bearing characteristics are added into the spindle model through structural modification. Then, the centrifugal force and gyroscopic effect caused by the high-speed rotation of the micro-milling spindle are considered to better simulate the real scenario and increase the accuracy of modal parameters. The method has general usage and can be applied to all the micro-milling tools under which only the spindle dimension, bearing characteristics, and contact parameters need to be changed.


2022 ◽  
Vol 165 ◽  
pp. 108311
Author(s):  
Xue-Bin Dang ◽  
Min Wan ◽  
Wei-Hong Zhang ◽  
Yun Yang

Author(s):  
Kang-Jae Lee ◽  
M. Alkan Donmez

Stability analysis is needed to maximize milling performance while avoiding chatter. However, such an analysis is time-consuming, requiring the use of sophisticated instrumentation, and has significant level of uncertainty, which impedes the widespread use by industry. A main source of uncertainty is believed to be the changes in dynamics of the tool-holder-spindle system during the milling operation. This study investigates the variation in the tool point dynamics reflecting the dynamics of the tool-holder-spindle system and associated machining stability. The investigation focuses on the effects of the conditions generated by typical milling operations, such as tool changes and spindle warm up. The results of analyses demonstrate the necessity of continuous updates of the tool point dynamics during milling process by in-situ measurements to minimize uncertainty in evaluation of machining stability.


2011 ◽  
Vol 418-420 ◽  
pp. 840-843
Author(s):  
Qing Hua Song ◽  
Xing Ai

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.


1968 ◽  
Vol 90 (2) ◽  
pp. 330-334 ◽  
Author(s):  
R. Sridhar ◽  
R. E. Hohn ◽  
G. W. Long

In this paper, a method of stability analysis for the general milling process is given. The milling operation is described by a linear differential-difference equation with periodic coefficients. An algorithm which can be used in conjunction with the digital computer is developed as a means of analytically determining the stability of this equation. This algorithm will permit the determination of the stability boundaries in the space of controllable parameters associated with a cutting operation and allows more realistic models for milling to be studied than have been attempted up to the present time. The technique is used to predict the stability in an example of a milling operation.


Author(s):  
Feng-Xia He ◽  
Li Dai ◽  
Qisen Chen ◽  
Yu Liu ◽  
Zhong Luo

Purpose Since robot’s structural stiffness is usually less than 1 N/µm, mode coupling chatter occurs frequently during robotic milling process, and chatter frequency is close to the natural frequency of the robot itself. Chatter not only affects the surface quality but also damages the robot and reduces the positioning accuracy. Therefore, it is necessary to predict chatter in robotic machining process. Design/methodology/approach A three-dimensional dynamic model for robot’s spatial milling plane is established, and a corresponding stability criterion is obtained. First, the cutting force in milling plane is transformed into the coordinate system of the robot principal stiffness direction based on homogeneous transformation matrix. Then the three-dimensional stability criterion under milling process can be obtained by using system stability analysis. Furthermore, the circle diagram of mode coupling chatter stability is drawn. Each feeding direction’s stability under the two processing forms, referred as spindle vertical milling and spindle horizontal milling, is analyzed. Findings The experimental results verify that the three-dimensional stability criterion can avoid chatter by selecting machining feed direction in stable area. Originality/value This paper established a three-dimensional dynamic model in robot’s spatial milling plane and proposed a three-dimensional stability criterion according to the Routh criterion. The work is also expected to be an efficient tool in the development of robotic milling technology.


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