Modeling and Simulation of the Dynamics of the Milling of Ball End Milling

2011 ◽  
Vol 130-134 ◽  
pp. 2364-2370
Author(s):  
Meng Qin Sun

A dynamic modal of the milling of ball end milling is presented for the simulation and analyzing the influence of the milling parameters on milling in order to avoid the vibration. The milling cutter and constrains are simplified to be a system with the two modes of vibration, the modal is developed considering effective cutting area of the cutting edge and regenerative effect, which directly reflects the cutter-in and the cutter-out. The mode testing and identifying determine the equation coefficients. It is found that reducing the milling depth can improve the stability and avoid self-excited vibration milling when the depth less than the critical milling depth, the frequency of the milling system will change while changing the rotate speed of the spindle, the self-excited is prone to occur when the frequency is close to the natural frequency. The results of simulation are benefit of the milling and optimal design of the parallel machine tools.

2010 ◽  
Vol 443 ◽  
pp. 302-307
Author(s):  
Jun Zhao ◽  
Xiao Feng Zhang ◽  
Han Bing Luo

By taking into account the regenerative chatter vibration, a nonlinear dynamics model for high speed ball-end milling is proposed. The effect of dynamic components of milling forces on chatter is analyzed. A method to predict the stability limits of high speed ball-end milling process is proposed and the stability lobes diagram is simulated. The comparison of experimental milling forces with the simulation results indicates the high accuracy of the model and the effectiveness of the simulation algorithms. The proposed method provides a theoretical instruction for parameters selection and optimization in milling processing.


Author(s):  
Erdem Ozturk ◽  
Erhan Budak

Being one of the most important problems in machining, chatter vibrations must be avoided as they result in high cutting forces, poor surface finish, and unacceptable part quality. Using stability diagrams is an effective method to predict chatter free cutting conditions. Although there have been numerous works in milling dynamics, the stability of five-axis ball-end milling has not been studied in detail. In this paper, the stability of the five-axis ball-end milling is analyzed using analytical (frequency domain), numerical (time-domain), and experimental methods. The models presented consider 3D dynamics of the five-axis ball-end milling process including the effects of all important process parameters such as the lead and tilt angles. Both single- and multi-frequency solutions are presented. Unlike other standard milling cases, it is observed that adding multi-frequency effects in the solution has marginal influence on the stability diagrams for five-axis ball-end milling operations due to effects of the ball-end milling geometry on the engagement region, thus, on the directional coefficients. The stability limits predicted by single- and multi-frequency methods are compared with time-domain simulations and experiments. Using the models and experimental results, the effects of the lead and tilt angles on the stability diagrams are also shown. The presented models can be used in analysis of five-axis ball-end milling dynamics as well as in the selection of the milling conditions for increased stability.


Author(s):  
Rafael dos Santos Pereira ◽  
Roosevelt Droppa ◽  
Mara Cristina Lopes de Oliveira ◽  
Renato Altobelli Antunes

2015 ◽  
Vol 15 (3) ◽  
pp. 293-300 ◽  
Author(s):  
Nandkumar N. Bhopale ◽  
Nilesh Nikam ◽  
Raju S. Pawade

AbstractThis paper presents the application of Response Surface Methodology (RSM) coupled with Teaching Learning Based Optimization Technique (TLBO) for optimizing surface integrity of thin cantilever type Inconel 718 workpiece in ball end milling. The machining and tool related parameters like spindle speed, milling feed, axial depth of cut and tool path orientation are optimized with considerations of multiple response like deflection, surface roughness, and micro hardness of plate. Mathematical relationship between process parameters and deflection, surface roughness and microhardness are found out by using response surface methodology. It is observed that after optimizing the process that at the spindle speed of 2,000 rpm, feed 0.05 mm/tooth/rev, plate thickness of 5.5 mm and 15° workpiece inclination with horizontal tool path gives favorable surface integrity.


Author(s):  
Alptunc Comak ◽  
Orkun Ozsahin ◽  
Yusuf Altintas

High-speed machine tools have parts with both stationary and rotating dynamics. While spindle housing, column, and table have stationary dynamics, rotating parts may have both symmetric (i.e., spindle shaft and tool holder) and asymmetric dynamics (i.e., two-fluted end mill) due to uneven geometry in two principal directions. This paper presents a stability model of dynamic milling operations with combined stationary and rotating dynamics. The stationary modes are superposed to two orthogonal directions in rotating frame by considering the time- and speed-dependent, periodic dynamic milling system. The stability of the system is solved in both frequency and semidiscrete time domain. It is shown that the stability pockets differ significantly when the rotating dynamics of the asymmetric tools are considered. The proposed stability model has been experimentally validated in high-speed milling of an aluminum alloy with a two-fluted, asymmetric helical end mill.


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