Numerical Simulation of Machined Surface Topography and Roughness in Milling Process

2005 ◽  
Vol 128 (1) ◽  
pp. 96-103 ◽  
Author(s):  
Tong Gao ◽  
Weihong Zhang ◽  
Kepeng Qiu ◽  
Min Wan
Keyword(s):  
Surface Topography ◽  
End Milling ◽  
Equation System ◽  
Milling Process ◽  
Cutting Edge ◽  
Machined Surface ◽  
Ball End Milling ◽  
Starting Point ◽  
Trajectory Equation ◽  
End Milling Process

Machined surface topography is very critical since it directly affects the surface quality, especially the surface roughness. Based on the trajectory equations of the cutting edge relative to the workpiece, a new method is developed for the prediction of machined surface topography. This method has the advantage of simplicity and is a mesh-independent direct computing method over the traditional interpolation scheme. It is unnecessary to discretize the cutting edge or to mesh the workpiece. The topography value of any point on the machined surface can be calculated directly, and the spindle runout can be taken into account. The simulation of machined surface topography is successfully carried out for both end and ball-end milling processes. In the end milling process, a fast convergence of solving the trajectory equation system by the Newton-Raphson method can be ensured for topography simulation at any node on the machined surface thanks to the appropriate choice of the starting point. In the ball-end milling process, this general algorithm is applicable to any machined surface. Finally, the validity of the method is demonstrated by several simulation examples. Simulation results are compared to experimental ones, and a good agreement is obtained.

A New Algorithm for the Numerical Simulation of Machined Surface Topography in Multiaxis Ball-End Milling

2008 ◽  
Vol 130 (1) ◽  
Author(s):  
Wei-Hong Zhang ◽  
Gang Tan ◽  
Min Wan ◽  
Tong Gao ◽  
David Hicham Bassir
Keyword(s):  
Numerical Simulation ◽  
Surface Topography ◽  
End Milling ◽  
Computing Time ◽  
Cutting Edge ◽  
Machining Parameters ◽  
Step Method ◽  
Time Step ◽  
Machined Surface ◽  
Ball End Milling

In milling process, surface topography is a significant factor that affects directly the surface integrity and constitutes a supplement to the form error associated with the workpiece deformation. Based on the tool machining paths and the trajectory equation of the cutting edge relative to the workpiece, a new and general iterative algorithm is developed here for the numerical simulation of the machined surface topography in multiaxis ball-end milling. The influences of machining parameters such as the milling modes, cutter runout, cutter inclination direction, and inclination angle upon the topography and surface roughness values are studied in detail. Compared with existing methods, the basic advantages and novelties of the proposed method can be resumed below. First, it is unnecessary to discretize the cutting edge and tool feed motion and rotation motion. Second, influences of cutting modes and cutter inclinations are studied systematically and explicitly for the first time. The generality of the algorithm makes it possible to calculate the pointwise topography value on any sculptured surface of the workpiece. Besides, the proposed method is proved to be more efficient in saving computing time than the time step method that is commonly used. Finally, some examples are presented and simulation results are compared with experimental ones.

Simulation of Surface Topography in Ball-End Milling Considering the Tool Deflection and Runout

2008 ◽  
Vol 375-376 ◽  
pp. 510-514 ◽  
Author(s):  
Jun Zhao ◽  
Xing Ai ◽  
Wen Yong Fang ◽  
Shi Guo Han
Keyword(s):  
End Milling ◽  
Milling Process ◽  
Tool Deflection ◽  
Machined Surface ◽  
Tool Runout ◽  
Ball End Milling ◽  
Proposed Model ◽  
Solid Ball ◽  
The Matrix ◽  
End Milling Process

The present work puts forward a generalized simulation model to evaluate the topography of ball-end milled surfaces by considering both the tool deflection and the tool runout. Firstly, a solid ball-end mill with S-shaped cutting edges is modeled as the basis. Then the tool tip trajectory is derived from the tool runout as well as the cutting forces induced tool deflection. And consequently the topography and scallop height of the machined surface are estimated by the numerical calculations of the matrix equations. With good expandibility, the proposed model can incorporate more machining information such as the movements of rotatory axes and tool wear, and hence, can be used to optimize the cutting conditions and parameters in 5-axis ball-end milling process.

Geometrical Modeling of Tool-Workpiece Contact Zone and Chip Formation in Finish Ball End Milling Process with Tool Inclination Angles

2016 ◽  
Vol 693 ◽  
pp. 788-794
Author(s):  
Xiao Xiao Chen ◽  
Jun Zhao
Keyword(s):  
Contact Zone ◽  
Measurement Method ◽  
End Milling ◽  
Milling Process ◽  
Ball End Milling ◽  
Geometrical Modeling ◽  
Section Area ◽  
Inclination Angles ◽  
Area And Perimeter ◽  
End Milling Process

The tool-workpiece contact zone is an important issue in the ball end milling process. This paper investigated the effects of tool inclination angles on the tool-workpiece contact zone, and variations of the cutting section area and perimeter with the increasing tilt and lead angles were also analyzed by geometrical modeling and measurement method for ball end milling process. The appropriate tool inclination angles, which could avoid the extrusion and friction between tool tip and the uncut materials, shorten the loading time on the cutting flute, and decrease the maximum cutting forces, could be preferentially selected according to the distribution characteristics of the tool-workpiece contact zone and the variations of the cutting section area and perimeter corresponding to various tool postures.

Intelligent Monitoring and Prediction of Surface Roughness in Ball-End Milling Process

2011 ◽  
Vol 121-126 ◽  
pp. 2059-2063 ◽  
Author(s):  
Somkiat Tangjitsitcharoen ◽  
Angsumalin Senjuntichai
Keyword(s):  
Surface Roughness ◽  
Cutting Force ◽  
Prediction Accuracy ◽  
End Milling ◽  
Milling Process ◽  
Ball End Milling ◽  
Roughness Model ◽  
Force Ratio ◽  
Tool Diameter ◽  
End Milling Process

In order to realize the intelligent machines, the practical model is proposed to predict the in-process surface roughness during the ball-end milling process by utilizing the cutting force ratio. The ratio of cutting force is proposed to be generalized and non-scaled to estimate the surface roughness regardless of the cutting conditions. The proposed in-process surface roughness model is developed based on the experimentally obtained data by employing the exponential function with five factors of the spindle speed, the feed rate, the tool diameter, the depth of cut, and the cutting force ratio. The prediction accuracy and the prediction interval of the in-process surface roughness model at 95% confident level are calculated and proposed to predict the distribution of individually predicted points in which the in-process predicted surface roughness will fall. All those parameters have their own characteristics to the arithmetic surface roughness and the surface roughness. It is proved by the cutting tests that the proposed and developed in-process surface roughness model can be used to predict the in-process surface roughness by utilizing the cutting force ratio with the highly acceptable prediction accuracy.

Generalized Mechanistic Force System Model of Ball-End Milling for Sculpture Surface Machining

2001 ◽  
Author(s):  
Ismail Lazoglu
Keyword(s):  
End Milling ◽  
Mechanistic Model ◽  
Milling Process ◽  
Force System ◽  
Workpiece Surface ◽  
Surface Machining ◽  
Ball End Milling ◽  
End Milling Process ◽  
Validation Experiments ◽  
Good Agreement

Abstract In this paper, a new mechanistic model is developed for the prediction of cutting force system in ball-end milling process. The key feature of the model includes the ability to calculate the workpiece / cutter intersection domain automatically for a given cutter location (CL) file, cutter and workpiece geometries. Moreover, an analytical approach is used to determine the instantaneous chip load and cutting forces. The model also employs a Boolean approach for given cutter, workpiece geometries, and the CL file in order to determine the surface topography and scallop height variations along the workpiece surface which can be visualized in 3-D. Some of the typical results from the model validation experiments performed on Ti-6A1-4V are also reported in the paper. Comparisons of the predicted and measured forces as well as the surface topographies show good agreement.

A HIGHER FIDELITY MODELING OF THE CUTTING EDGE OF BALL-END MILLING TOOL

2011 ◽  
Vol 10 (01) ◽  
pp. 101-108 ◽  
Author(s):  
XIULIN SUI ◽  
IMRE HORVATH ◽  
JIATAI ZHANG ◽  
PING ZHANG
Keyword(s):  
End Milling ◽  
Milling Process ◽  
Cutting Edge ◽  
Ball End Milling ◽  
Machining Conditions ◽  
Milling Tool ◽  
Efficient Planning ◽  
Pilot Implementation ◽  
Physical Changes ◽  
Milling Forces

Ball-end milling tools have been widely used in machining of complex freeform surfaces. The precision and efficiency of ball-end milling process can be improved by an accurate modeling of the tools, the tools' paths and the machining conditions. However, only rough geometric models have been applied so far, which do not consider the machining conditions and the physical changes. To achieve the best results, an accurate modeling of the cutting edge and the physical behavior of the entire cutter is needed. This paper proposes an articulated model that enumerates both the geometric characteristics and the physical effects acting on the cutting edge-segment of a ball-end milling cutter. The model considers the deformations caused by the milling forces, vibration, spindle eccentricity, together with thermal deformation and wear of the cutter. The mathematical description of the behavior has been transferred into a computational model. The pilot implementation has been tested in a practical application. The first findings show that the proposed theoretical model and implementation provide sufficiently precise information about the behavior of the cutter in virtual simulations; hence it can be the basis of a fully fledged and more efficient planning of milling processes.

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