scholarly journals Vibrations of Flat-End Cutter Entering Workpiece Process: Modeling, Simulations, and Experiments

2018 ◽  
Vol 2018 ◽  
pp. 1-23 ◽  
Author(s):  
Ming Luo ◽  
Qi Yao
Keyword(s):  
Cutting Forces ◽  
Chip Thickness ◽  
Machining Process ◽  
Time Varying ◽  
Time Domain Simulation ◽  
Cutting Depth ◽  
Machined Surface ◽  
Dynamic Cutting Force ◽  
Force Calculation ◽  
Cycle Path

During all the machining process, the milling cutter has to enter the workpiece either from the boundary or from the machined/unmachined surface, due to the change of machining sequence/cutter or the variation of cutting depth. Unlike the stable cutting process, the contact between cutter and machined workpiece changes significantly in the entering process, resulting in vibration and leaving marks on the machined surface. Aiming at in-depth understanding the mechanism of this phenomenon, this paper presents a novel time-domain simulation model to predict the dynamic response of the cutter during the entering process. Two typical entering conditions, including entering from the workpiece boundary and from the machined surface along the cycle path, are modeled based on the dynamic cutting force calculation by considering dynamic undeformed chip thickness created by consequential teeth engagement. Then, it is synthesized with the time-varying immersion angle and exit angle of cutter teeth in the entering process to simulate the dynamic cutting forces and cutter vibrations. To validate the developed model, eight conditions in boundary entering and six conditions in cycle path entering are carried out by comparing the collected data and the predicted results. Results show that the developed model could precisely predict the dynamic cutting forces and cutter vibration, especially the forces and displacements under the varied cutter-workpiece contact.

Study on the machining process of micro V-shaped groove by using a revolving tip

2017 ◽  
Vol 232 (9) ◽  
pp. 1523-1537
Author(s):  
Bo Xue ◽  
Yongda Yan ◽  
Gaojie Ma ◽  
Zhenjiang Hu
Keyword(s):  
Cutting Forces ◽  
Chip Thickness ◽  
Chip Morphology ◽  
Machining Process ◽  
Burr Formation ◽  
Uncut Chip Thickness ◽  
Machined Surface ◽  
Advantages And Disadvantages

This paper proposed a machining method for micro V-shaped grooves, which was achieved by introducing the revolving trajectory on the basis of tip scratching process. By coordinating the revolving direction and the tip orientation, four kinds of revolving scratches were developed which had the revolving radii larger than the groove depths. It was found that there were two revolving scratches among these four being able to eliminate the side burrs and produce much smaller cutting forces during machining grooves compared to the traditional scratch, respectively named as the up-milling of face-forward and the down-milling of edge-forward. By considering the tip geometry in the traditional scratching process, the burr formation has been studied which was mainly affected by the effect of chip interference and the amount of uncut chip thickness. By analyzing the machining trajectory, the undeformed chip, the machined surface and the chip morphology, the reason why the up-milling of face-forward and the down-milling of edge-forward had good performances for machining V-grooves was elucidated in detail. Meanwhile, the differences between these two revolving scratches were discussed, and their advantages and disadvantages were also given.

Cutting Force Analysis to Determine the Performance of Micro End Milling Process of Silicon Wafer

2007 ◽  
Author(s):  
Rusnaldy ◽  
Tae Jo Ko ◽  
Hee Sool Kim
Keyword(s):  
Cutting Force ◽  
Silicon Wafer ◽  
Cutting Forces ◽  
End Milling ◽  
Chip Thickness ◽  
Tool Material ◽  
Machining Process ◽  
Tool Geometry ◽  
Machined Surface ◽  
Micro End Milling

There is a lack of fundamental understanding of micro-end-milling of silicon wafer, specifically basic understanding of material removal mechanism, cutting forces and machined surface integrity in micro scale machining of silicon. It is necessary to determine the forces generated during the cutting operation due to chip thickness along with tool geometry, tool material properties and workpiece properties because cutting forces will provide vital information for the design, modeling and control of the machining process. In this study, cutting force data can be used to determine cutting regime machining of silicon wafer.

Analysis of the effect of tool posture on stability considering the nonlinear dynamic cutting force coefficient

2021 ◽  
pp. 1-19
Author(s):  
Zepeng Li ◽  
Rong Yan ◽  
Xiaowei Tang ◽  
Fang Yu Peng ◽  
Shihao Xin ◽  
...  
Keyword(s):  
Cutting Force ◽  
Nonlinear Dynamic ◽  
Chip Thickness ◽  
Cutting Depth ◽  
Force Coefficient ◽  
Critical Cutting Depth ◽  
Dynamic Cutting Force ◽  
Cutting Force Coefficient ◽  
Tool Posture ◽  
Instantaneous Uncut Chip Thickness

Abstract In aviation and navigation, complicated parts are milled with high-speed low-feed-per-tooth milling to decrease tool vibration for high quality. Because the nonlinearity of the cutting force coefficient (CFC) is more evident with the relatively smaller instantaneous uncut chip thickness, the stable critical cutting depth and its distribution against different tool postures are affected. Considering the nonlinearity, a nonlinear dynamic CFC model that reveals the effect of the dynamic instantaneous uncut chip thickness on the dynamic cutting force is derived based on the Taylor expansion. A five-axis bull-nose end milling dynamics model is established with the nonlinear dynamic CFC model. The stable critical cutting depth distribution with respect to tool posture is analyzed. The stability results predicted with the dynamic CFC model are compared with those from the static CFC model and the constant CFC model. The effects of tool posture and feed per tooth on stable critical cutting depth were also analyzed, and the proposed model was validated by cutting experiments. The maximal stable critical cutting depths that can be achieved under different tool postures by feed per tooth adjustment were calculated, and corresponding distribution diagrams are proposed for milling parameter optimization.

scholarly journals Analysis of Forces in Vibro-Impact and Hot Vibro-Impact Turning of Advanced Alloys

2011 ◽  
Vol 70 ◽  
pp. 315-320 ◽  
Author(s):  
Riaz Muhammad ◽  
Agostino Maurotto ◽  
Anish Roy ◽  
Vadim V. Silberschmidt
Keyword(s):  
Finite Element ◽  
Cutting Forces ◽  
Three Dimensional ◽  
Element Model ◽  
Machining Process ◽  
Strain Rates ◽  
Machining Processes ◽  
Machined Surface ◽  
Cutting Zone

Analysis of the cutting process in machining of advanced alloys, which are typically difficult-to-machine materials, is a challenge that needs to be addressed. In a machining operation, cutting forces causes severe deformations in the proximity of the cutting edge, producing high stresses, strain, strain-rates and temperatures in the workpiece that ultimately affect the quality of the machined surface. In the present work, cutting forces generated in a vibro-impact and hot vibro-impact machining process of Ti-based alloy, using an in-house Ultrasonically Assisted Turning (UAT) setup, are studied. A three-dimensional, thermo-mechanically coupled, finite element model was developed to study the thermal and mechanical processes in the cutting zone for the various machining processes. Several advantages of ultrasonically assisted turning and hot ultrasonically assisted turning are demonstrated when compared to conventional turning.

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.

Experimental Study of the Dynamic Behavior of Thin-Walled Tubular Workpieces in Turning Cutting Process

2020 ◽  
pp. 1-19
Author(s):  
Zied Sahraoui ◽  
Kamel Mehdi ◽  
Moez Ben Jaber
Keyword(s):  
Dynamic Behavior ◽  
Cutting Forces ◽  
Chip Thickness ◽  
Cutting Process ◽  
Machining Process ◽  
Structural Damping ◽  
Turning Process ◽  
Manufactured Products ◽  
Thin Walled ◽  
The Stability

Nowadays, industrialists, especially those in the automobile and aeronautical transport fields, seek to lighten the weight of different product components by developing new materials lighter than those usually used or by replacing some massive parts with thin-walled hollow parts. This lightening operation is carried out in order to reduce the energy consumption of the manufactured products while guaranteeing optimal mechanical properties of the components and increasing quality and productivity. To achieve these objectives, some research centers have focused their work on the development and characterization of new light materials and some other centers have focused their work on the analysis and understanding of the encountered problems during the machining operation of thin-walled parts. Indeed, various studies have shown that the machining process of thin-walled parts differs from that of rigid parts. This difference comes from the dynamic behavior of the thin-walled parts which is different from that of the massive parts. Therefore, the purpose of this paper is to first highlight some of these problems through the measurement and analysis of the cutting forces and vibrations of tubular parts with different thicknesses in AU4G1T351 aluminum alloy during the turning process. The experimental results highlight that the dynamic behavior of turning process is governed by large radial deformations of the thin-walled workpieces and the influence of this behavior on the variations of the chip thickness and cutting forces is assumed to be preponderant. The second objective is to provide manufacturers with a practical solution to the encountered vibration problems by improving the structural damping of thin-walled parts by additional damping. It is found that the additional structural damping increases the stability of the cutting process and reduces considerably the vibrations amplitudes.

Methodic of Rational Cutting Conditions Determination for 3-D Shaped Detail Milling Based on the Process Numerical Simulation

2014 ◽  
Author(s):  
Igor Kiselev ◽  
Sergey Voronov
Keyword(s):  
Cutting Forces ◽  
Complex Geometry ◽  
Chip Thickness ◽  
Cutting Conditions ◽  
Dynamical Model ◽  
Processing Route ◽  
Technological Parameters ◽  
Machined Surface ◽  
Geometry Modeling ◽  
Milling Dynamics

The paper is devoted for the analysis of the dynamics effect on the 5-axis milling process of flexible details. The integrated model of milling dynamics composed by block principle in the paper is presented. The model consist of: 1) dynamical model of tool; 2) dynamical model of machined detail based on Finite Element Method (FEM); 3) phenomenological model of cutting forces and 4) algorithm of geometry modeling for instant machined chip thickness calculation. Regeneration mechanism of cutting and calculation of the machined surface are into this algorithm embedded. The elaborated model is adapted for 5-axis processing of the profiled details with 3-D complex geometry. Alteration of workpiece dynamic characteristics while the allowance removal is considered by the special algorithm of FEM grid changing based on the results of cutting geometry modeling. The results of modeling give us opportunity determine cutting forces, estimate the machined surface quality, calculate the magnitude and the character of tool and detail vibrations under the specified cutting conditions. The conception of increasing the process quality and the machinability for 3-D shaped details machining is offered in the paper. Applying the specified efficient conditions the undesired dynamical effects can be excluded on the base of the results of multi-variant simulation for milling dynamics varying the technological parameters at the different region of the processing route.

scholarly journals Generic Mathematical Model for Efficient Milling Process Simulation

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Hilde Perez ◽  
Eduardo Diez ◽  
Juan de Juanes Marquez ◽  
Antonio Vizan
Keyword(s):  
Mathematical Model ◽  
Cutting Force ◽  
Process Simulation ◽  
Cutting Forces ◽  
Metal Cutting ◽  
Chip Thickness ◽  
Machining Process ◽  
Force Estimation ◽  
Peripheral Milling ◽  
Simulation And Optimization

The current challenge in metal cutting models is to estimate cutting forces in order to achieve a more accurate and efficient machining process simulation and optimization system. This paper presents an efficient mathematical model for process simulation to evaluate the cutting action with variable part geometries of helical cutters and predict the cutting forces involved in the process. The objective of this paper has been twofold: to improve both the accuracy and computational efficiency of the algorithm for cutting force estimation in peripheral milling. Runout effect and the real tool tooth trajectory are taken into account to determine the instantaneous position of the cutting flute. An expression of average chip thickness for the engaged flute in the cut is derived for cutting force calculations resulting in a more efficient process simulation method in comparison with previous models. It provides an alternative to other studies in scientific literature commonly based on numerical integration. Experiments were carried out to verify the validity of the proposed method.

Simulation and Experimental Study on Size Effect in Steel Micro Milling Machining Process

2012 ◽  
Vol 602-604 ◽  
pp. 2021-2026 ◽  
Author(s):  
Chun Jiang Zhou ◽  
Jian Cheng Liu
Keyword(s):  
Size Effect ◽  
High Speed ◽  
Chip Thickness ◽  
Critical Factor ◽  
Machining Process ◽  
Micro Milling ◽  
Exit Point ◽  
Machining Processes ◽  
Machined Surface ◽  
Optimal Cutting Parameters

Size effect is a critical factor that needs to be considered when conducting micro mechanical machining processes. In this paper, a cutting process simulation technology is used to simulate a single tooth’s engagement with workpiece from the entry point to the exit point in a slot milling operation. The obtained specific cutting forces from simulation are employed to analyze the size effect and the minimum chip thickness with variable radii of tool edges. Micro machining experiments with different machining conditions are implemented by use of a high speed and high precision machining spindle to investigate the size effect on machined surface integrity and burr width. The optimal cutting parameters have been analyzed based on the simulation and cutting test results.

A Numerical and Experimental Investigation of the Deformation Zones and the Corresponding Cutting Forces in Orthogonal Cutting

2011 ◽  
Vol 223 ◽  
pp. 152-161 ◽  
Author(s):  
Mathias Agmell ◽  
Aylin Ahadi ◽  
Jan Eric Ståhl
Keyword(s):  
Experimental Data ◽  
Cutting Forces ◽  
Orthogonal Cutting ◽  
Chip Thickness ◽  
Thickness Ratio ◽  
Machining Process ◽  
Work Piece ◽  
Fe Model ◽  
Force Measurements ◽  
Fully Coupled

This study are focused on the deformation zones occurring in the work piece in a machining process and the corresponding cutting forces. The fully coupled thermo-mechanical FE-model for orthogonal cutting, developed in [1] is utilized. The work piece material is modeled with Johnson-Cook plasticity including damage formulation. Simulations for different feed depths were performed. The cutting forces, the chip thickness ratio and the deformation widths were determined experimentally by the quick-stop images and a force measurements. The results from the simulations have been compared to experimental data for the cutting forces and the chip thickness ratio as a function of the theoretical chip thickness.

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