Force Modeling of Five-Axis Microball-End Milling

2015 ◽  
Vol 3 (3) ◽  
Author(s):  
Chi Xu ◽  
James Zhu ◽  
Shiv G. Kapoor
Keyword(s):  
End Milling ◽  
Elastic Recovery ◽  
Chip Thickness ◽  
Force Model ◽  
End Mill ◽  
Data Simulation ◽  
Force Modeling ◽  
Static Indentation ◽  
Five Axis ◽  
Milling Force Model

This paper presents a five-axis ball-end milling force model that is specifically tailored to microscale machining. A composite cutting force is generated by combining two force contributions from a shearing/ploughing slip-line (SL) field model and a quasi-static indentation (ID) model. To fully capture the features of microscale five-axis machining, a unique chip thickness algorithm based on the velocity kinematics of a ball-end mill is proposed. This formulation captures intricate tool trajectories as well as readily allows the integration of runout and elastic recovery effects. A workpiece updating algorithm has also been developed to identify tool–workpiece engagement. As a dual purpose, historical elastic recovery is stored locally on the meshed workpiece surface in vector form so that the directionality of elastic recovery is preserved for future time increments. The model has been validated through a comparison with five-axis end mill force data. Simulation results show reasonably accurate replication of end milling cutting forces with minimal experimental data fitting.

Voxel Based Cutting Force Simulation of Ball End Milling Considering Cutting Edge Around Center Web

2018 ◽  
Author(s):  
Isamu Nishida ◽  
Takaya Nakamura ◽  
Ryuta Sato ◽  
Keiichi Shirase
Keyword(s):  
Cutting Force ◽  
End Milling ◽  
Chip Thickness ◽  
Previous Method ◽  
Cutting Edge ◽  
Force Model ◽  
End Mill ◽  
Uncut Chip Thickness ◽  
Ball End Mill ◽  
Tool Rotation

A new method, which accurately predicts cutting force in ball end milling considering cutting edge around center web, has been proposed. The new method accurately calculates the uncut chip thickness, which is required to estimate the cutting force by the instantaneous rigid force model. In the instantaneous rigid force model, the uncut chip thickness is generally calculated on the cutting edge in each minute disk element piled up along the tool axis. However, the orientation of tool cutting edge of ball end mill is different from that of square end mill. Therefore, for the ball end mill, the uncut chip thickness cannot be calculated accurately in the minute disk element, especially around the center web. Then, this study proposes a method to calculate the uncut chip thickness along the vector connecting the center of the ball and the cutting edge. The proposed method can reduce the estimation error of the uncut chip thickness especially around the center web compared with the previous method. Our study also realizes to calculate the uncut chip thickness discretely by using voxel model and detecting the removal voxels in each minute tool rotation angle, in which the relative relationship between a cutting edge and a workpiece, which changes dynamically during tool rotation. A cutting experiment with the ball end mill was conducted in order to validate the proposed method. The results showed that the error between the measured and predicted cutting forces can be reduced by the proposed method compared with the previous method.

End Milling Force Model Calibration Using Measured Force Profiles

2012 ◽  
Author(s):  
Yong Zhao ◽  
Robert B. Jerard ◽  
Barry K. Fussell
Keyword(s):  
Cutting Force ◽  
End Milling ◽  
Chip Thickness ◽  
Force Sensor ◽  
Force Model ◽  
Experimental Conditions ◽  
Cutting Coefficients ◽  
Force Profile ◽  
Milling Force Model ◽  
Force Profiles

This paper introduces a method to use the cutting force profile, measured from a Kistler dynamometer, to calibrate a mechanistic based force model containing four cutting coefficients. The undesirable effects of tool vibration and force sensor dynamics are minimized by carefully choosing experimental conditions. Cutting force profiles provide an array of force versus chip thickness based values that can be used in a regression fit to find the model coefficients. Results show that different ranges of chip thickness used in the calibration process result in slightly different cutting coefficients, which implies chip thickness has an effect on cutting coefficients. The force profile based cutting coefficients are then used in the cutting force model to estimate the peak resultant cutting force. Comparison of model estimates and measured values show less than 10% error.

Instantaneous Uncut Chip Thickness Model in End Milling Based on an Improved Method

2018 ◽  
Vol 764 ◽  
pp. 399-407
Author(s):  
Yue Zhang ◽  
Zhi Qiang Yu ◽  
Tai Yong Wang
Keyword(s):  
End Milling ◽  
Chip Thickness ◽  
Transcendental Equation ◽  
Milling Process ◽  
Force Model ◽  
Uncut Chip Thickness ◽  
Milling Force ◽  
Milling Force Model ◽  
Instantaneous Uncut Chip Thickness ◽  
Taylor’S Series

The instantaneous uncut chip thickness is an important parameter in the study of milling force model. By analyzing the real tooth trajectory in milling process, accurate instantaneous uncut chip thickness can be obtained to solve the complex transcendental equation. Traditional chip thickness models always simplify the tooth trajectory to get approximate solution. A new instantaneous uncut chip thickness model is proposed in this paper. Based on real tooth trajectory of general end milling cutter, a Taylor's series is used to approximate the involved infinitesimal variable in the transcendental equation, which results in an explicit expression for practical application of the uncut chip thickness with higher accuracy compared to the traditional model.

Modeling and Simulation of Milling Force in Virtual Numerical Control Milling Process

2008 ◽  
Vol 392-394 ◽  
pp. 697-702
Author(s):  
Xiu Lin Sui ◽  
Jia Tai Zhang ◽  
Jiang Hua Ge ◽  
Ya Ping Wang ◽  
H. Yuan
Keyword(s):  
Modeling And Simulation ◽  
Chip Thickness ◽  
Milling Process ◽  
Cutting Edge ◽  
Numerical Control ◽  
Force Model ◽  
End Mill ◽  
Ball End Mill ◽  
Milling Force ◽  
Milling Force Model

A parameter equation based on cutting edge of ball-end mill is set up by analyzing the parameters of ball-end mill influence the milling force in virtual NC milling process. The relationship among elemental cutting force, instantaneous radial chip thickness and cutting edge length is analyzed, and the dynamic milling force of ball-end mill at arbitrary feed direction is established. The milling force parameter model by quadratic regression equation in different cutting conditions is built. Through experiments in NC machining center and using orthogonal combination and principal components analysis, the regression coefficients are calculated. The correctness of milling force model is testified by experiments. All these can provide theoretical basis for physics modeling and simulation of virtual numerical control milling.

A generalized cutting force model for five-axis milling processes

2017 ◽  
Vol 233 (1) ◽  
pp. 3-17 ◽  
Author(s):  
Qinghua Song ◽  
Zhanqiang Liu ◽  
Ganggang Ju ◽  
Yi Wan
Keyword(s):  
Chip Thickness ◽  
Milling Process ◽  
Normal System ◽  
Force Model ◽  
Sculptured Surfaces ◽  
End Mill ◽  
Peripheral Milling ◽  
Ball End Mill ◽  
Milling Cutter ◽  
Five Axis

A generalized mechanical model is proposed to predict cutting forces for five-axis milling process of sculptured surfaces with generalized milling cutter, which is considered as a revolution around tool axis of an arbitrary section curve composed of variable lines and curves. Solid-analytical-based method is presented and extended to precisely and efficiently identify the cutter–workpiece engagements between the generalized milling cutter and workpiece being machined. And the undeformed chip thickness is calculated with respect to pre-defined tool coordinate system, which is regarded as the transformation form of feed cross–feed normal system by lead and tilt angles. Although only two experimental validations (peripheral milling with cylinder end mill and multi-axis milling with ball end mill) are performed to estimate the robustness and flexibility of the method presented, it can be applied for an arbitrary mill geometry in multi-axis milling as well as three-axis milling, two-and-a-half-axis milling. Finally, a case study of aero-engine impeller five-axis milling with ball end mill is performed to further illustrate the validation of the model.

A Mechanistic Force Model of the 5-Axis Milling Process

2000 ◽  
Author(s):  
Paul A. Clayton ◽  
Mohamed A. Elbestawi ◽  
Tahany El-Wardany ◽  
Dan Viens
Keyword(s):  
High Speed ◽  
Mechanistic Model ◽  
Back Propagation ◽  
High Speed Steel ◽  
Cutting Edge ◽  
Analytic Description ◽  
Force Model ◽  
Force Output ◽  
Five Axis ◽  
Milling Force Model

Abstract This paper presents a five-axis milling force model that can incorporate a variety of cutters and workpiece materials. The mechanistic model uses a discretized cutting edge to calculate an area of intersection which is multiplied by the specific cutting pressure to produce a force output along the primary cartesian coordinate system. By using an analytic description of the cutting edge with a non-specific cutter and workpiece intersection routine, a model was created that can describe a variety of cutting situations. Furthermore, a back propagation neural network is used to calibrate the model, providing robustness and scalability to the calibration process. Testing was performed on 1020 steel using various cutting parameters with a high speed steel two flute cutter and a tungsten carbide insert cutter. Furthermore, both linear cuts and a test die surface yielded good agreement between predicted and measured results.

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.

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.

High-Quality Machining of Edges of Thin-Walled Plates by Tilt Side Milling Based on an Analytical Force-Based Model

2019 ◽  
Vol 141 (6) ◽  
Author(s):  
Gongyu Liu ◽  
Jiaqiang Dang ◽  
Weiwei Ming ◽  
Qinglong An ◽  
Ming Chen ◽  
...  
Keyword(s):  
Cutting Force ◽  
Tilt Angle ◽  
Chip Thickness ◽  
Assessment Model ◽  
Force Model ◽  
High Quality ◽  
Machined Surface ◽  
Side Milling ◽  
Thin Walled ◽  
Milling Force Model

The milling of thin-walled workpieces is a common process in many industries. However, the machining defects are easy to occur due to the vibration and/or deformation induced by the poor stiffness of the thin structures, particularly when side milling the edges of plates. To this problem, an attempt by inclining the tool to a proper tilt angle in milling the edges of plates was proposed in this paper, in order to decrease the cutting force component along the direction of the lowest stiffness of the plates, and therefore to mitigate the machining vibration and improve the machined surface quality effectively. First, the milling force model in consideration of the undeformed chip thickness and the tool-workpiece engagement (TWE) was introduced in detail. Then, a new analytical assessment model based on the precisely established cutting force model was developed so as to obtain the optimum tool tilt angle for the minimum force-induced defects after the operation. Finally, the reliability and correctness of the theoretical force model and the proposed assessment model were validated by experiments. The methodology in this paper could provide practical guidance for achieving high-quality machined surface in the milling operation of thin-walled workpieces.

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