Simulation Of Milling Process Research Articles

Damping effect on chatter stability of turning and milling processes

This paper applies damping effect to turning and milling processes in order to enhance their chatter stability while they are in operation. The processes dynamic models and their analytical solutions were presented in detail. The models of the two processes were separately used in MatLab/Simulink with the aid of data from actual cutting tests in order to predict the processes dynamic stability. The developed model and its analytical solution for milling process have been verified by actual milling test. Then the generated stability lobe diagrams with/without damping were compared for each process. The results show that the stable cutting zone is remarkably increased for the employed low cutting speeds. The simulation and experimental results of the damped milling process are consistent. In general, this simulation approach can have practical interest especially in machining of high performance aeronautical hard-to-cut materials.

Method for optimum calculus of machining parameters according to tool trajectories type based on milling process simulation

Method for optimum calculus of machining parameters according to tool trajectories type based on milling process simulation

Simulation of the plain milling process

The article considers the dynamics of the plain milling process. The model takes into account the time-lag effect due to the algorithm of new surface formation during material cutting-off. A reduced model based on the results of a modal analysis of the milling cutter is applied to describe the dynamics of the tool. The results of the work are presented in the comparison of the microprofiles obtained as a result of processing and simulation of surfaces.

DETERMINATION OF CUTTING TEMPERATURE WHILE MILLING TITANIUM ALLOY BY FACE MILLS

In this article, the analysis process features high-speed cutting, which mainly attributed to the cutting temperatures depending on the speed of processing. Shows that depending on the design and tool size main criterion decrease temperature cutting not always characterized by high-speed processing. The reason for this is the rise temperature to values at which to change properties of the materials surface layer. To determine the cutting temperature of titanium alloys processing, we carried mechanical milling process simulation with mill O160 by finite element method. Defined temperature on contact surfaces at cutting speeds between 80 and 250 m/min. In this range of speed observed temperature cutting increase. Established, with cutting speeds higher 80 m/min workpiece surface have temperature at which the fragile layer formed. The simulation results verified experimentally in the milling of titanium alloy VT6.

Flat Milling Process Simulation Taking into Consideration a Dependence of Dynamic Characteristics of the Machine

Flat Milling Process Simulation Taking into Consideration a Dependence of Dynamic Characteristics of the Machine

3-D finite element process simulation of micro-end milling Ti-6Al-4V titanium alloy: Experimental validations on chip flow and tool wear

Finite element (FE) simulation of machining can be used as a replacement or a supplementary to the physical experiment allowing an analysis to be performed at a lower cost. Besides, FE simulation can offer predictions of process variables which are difficult to obtain by experiment. This paper provides investigations on 3-D FE modeling and simulation of micro-end milling process for Ti-6Al-4V titanium alloy. 3-D FE models proposed for full-immersion, half immersion up and down milling are utilized to study the influence of increasing tool edge radius due to wear on the process performance of micro-end milling. Predicted 3-D chip flow and shapes are compared against the experiments which provided reasonably good agreements. Tool wear along the micro-end milling tool is predicted and validated with experiments. The results of this study indicated that tool wear has a significant impact to the cutting force, cutting temperature, tool wear rate, chip flow and burr formation. In addition, a comparison of 3-D and 2-D FE simulations is provided giving a better understanding of utilizing their predictions.

Modeling, simulation, and optimization of five-axis milling processes

The five-axis milling is widely applied to complex surface machining. When cutting forces of milling processes increase, the consequent workpiece and tool deflections may result in poor machining quality and high processing cost. There are a lot of researches on three-axis milling processes simulation, but very few about five-axis milling. To solve these disadvantages, this paper presents an integrated system containing modeling, simulation, and optimization of five-axis milling processes. The system has three major applications: (1) simulation verification of milling processes, (2) cutting forces prediction, and (3) cutting parameters (feedrate) optimization. The material removal process simulation used for verifying the five-axis milling is based on the three-dexel (depth element) model, and the cutter-workpiece engagement regions are extracted from the geometric model. According to the extracted cutter-workpiece engagement regions, the instantaneous cutting forces could be predicted. The feedrate is off-line modified for balancing the given maximum or the reference cutting forces with the predicted cutting forces on different machining steps. The developed system is validated experimentally to show that the modeling, simulation, and optimization methods could improve the accuracy and efficiency of five-axis milling processes.

The Minimum Cutting Thickness in Milling Process Simulation Analysis

In order to study the phenomenon of micro-milling process influenced by the minimumcutting thickness, the milling thickness calculation model was established considering the minimumcutting thickness. For the sake of studying the effect of the failure of micro-milling cutter andsurface qualification of workpiece influenced by the minimum cutting thickness phenomenon,establish the milling model to simulate stress distribution and temperature distribution on thecondition of minimum cutting thickness in the process of micro-milling.

Extracting cutter/workpiece engagements in five-axis milling using solid modeler

Predicting cutting forces in milling process simulation requires finding cutter/workpiece engagements (CWEs). The calculation of these engagements is challenging due to the complicated and changing intersection geometry between the cutter and the in-process workpiece. In this paper, a solid modeling based methodology for finding CWEs generated in five-axis milling of free form surfaces is presented. The proposed methodology is an extension of the solid modeler based three-axis CWE extraction method given in [21]. At any given instant of the five-axis tool motion, the velocity vectors along the cutter axis may move in directions that do not lie in the same plane, and therefore the cutter envelopes need to be approximated by spline surfaces. Considering the spline surface approximations, the CWE methodology described in [21] does not work properly for the five-axis milling. Therefore in the proposed method, the in-process workpiece is used instead of the removal volume for extracting the CWEs. A terminology the feasible contact surfaces (FCS), defined by the envelope boundaries, is introduced. To extract the CWEs at a given cutter location, first the BODY entity, obtained by offsetting the FCS with an infinitesimal amount, is intersected with the in-process workpiece. Then, the resultant removal volume is decomposed into faces. Finally, the surface/surface intersections are performed between those faces and the FCS to obtain the CWE boundaries. To be used in the force model, the CWE boundaries are mapped from Euclidean 3D space to a parametric space defined by the engagement angle and the depth-of-cut for a given tool geometry.

Error prediction and compensation based on interference-free tool paths in blade milling

We propose a method which uses interference-free tool paths to predict and compensate for deformation error during the spiral milling of blades. Firstly, a finite element simulation of the blisk blade milling process was conducted using an interference-free spiral milling NC machining tool path based on the curvature attribute of the blade twisted surface, observing the variation in blade milling error under different processing parameters and yielding a surface quality variation law. Next, the model was corrected by combining this error prediction data with precision design requirements, and a blade deformation error compensation scheme was suggested. Finally, an interference-free processing program containing the error compensation information was applied to carry out another blade milling simulation and a blisk milling experiment. The results showed that both the blade deformation error and the surface quality satisfied design requirements, while the accuracy of the simulation was verified.

Numerical Simulation of Milling Process: A Total Procedure

Milling is one of the most common materials removal processes used in the production of dies, moulds and various aeronautic components. The process performances such as dimensional accuracy, chatter propagation and tool wear are the common problems which can lead to useless workpiece. The traditional method to avoid these problems is the so-called trial and error method, which often has the characteristics of time-consuming. With the advancement of recent computing techniques, one efficient method to determine acceptable process parameters is development of a comprehensive simulation environment. In this paper, efforts are focused on the introduction of a milling simulation procedure proposed recently by the research group of the authors. The key issues such as development of cutting force model, prediction of dimensional errors and stability lobes are described. At the same time, the crucial issues such as calibration of model parameters and simulation algorithms are also highlighted.

3D FE-Based Modelling and Simulation of the Micro Milling Process

Modelling and simulation of the micro milling process has the potential to improve tool design and optimize cutting conditions. This paper presents a novel and effective 3D finite element (FE) based method for simulating the micro milling process under large deformations. A tooling model incorporating a helix angle is developed for cutting forces, tooling temperature and chip formation prediction. The proposed approach is experimentally validated and the simulated micro milling performance such as micro chip formation and cutting forces are in reasonable agreement with the measured results in cutting trials.

An improved dynamic milling force coefficients identification method considering edge force

The identification of the dynamic coefficients is the key to realize accurate simulation of dynamic milling process. To enlarge the scope of dynamic simulation without ignoring edge force, an improved method is presented to calculate milling force coefficients. In this method, linear approximation of average milling force is integrated with multiple linear regressions by supposing that milling force coefficients are time invariant for small variation of feed rate. Therefore, both the shear coefficients and the edge coefficients can be calculated simultaneously. A comparison of simulated milling force with and without the edge force is illustrated and the result shows that the accuracy is higher if the edge force coefficients are considered. This method casts new light on fast and accurate simulation of the dynamic milling force in real industrial environment.

Milling Process Simulation Based on Quadtree-Array Representation

Model representation of workpiece in machining process simulation does directly influence on simulation accuracy and efficiency. The algorithm to acquire cutting width and cutting depth based on quadtree-array representation is discussed in this paper. In milling process simulation, workpiece is represented with quadtree-array and the cutting width and cutting depth are predicted real-time. The results of controlled simulation shows that the predicted cutting depth is accordance with that of the designed and the predicted cutting width is close to that of the designed within accuracy of half a discretization interval.

The Geometric Modeling of Pieces in Virtual Milling Simulation

The process simulation of virtual machining is the key technique in the CNC simulation system. So the paper talks about some useful geometric modeling techniques in simulation field, and bring forward an improved object-space separating modeling technique based on the idea of Dexel and the data-type of Z-MAP, which is a kind of geometric modeling for pieces for milling process simulation. This method is to a certain degree reduced calculation quantities in simulation, increased the speed of simulation and optimized the effect of simulation.

Analysis and Research of the Vibration of the High-Speed Cutting Process

The paper takes the dynamic cutting process as research subject to analyze and research the high-speed milling process. Through carrying out the dynamical modeling and simulation of the milling process, the analytical model of the dynamic cutting force and the chatter stable region of the spiral end mill were established. On the basis of the analytical model, the simulation of the end milling process was carried out, and the interpretational domain of the simulation was confirmed experimentally. Finally, the parameter optimization of the high-speed cutting process was investigated in the term of the stability of the cutting process.

Simulation of End Milling for Weak-Rigidity Structural Parts of Aluminium Alloy in Aviation

To resolve the problem of the parts deformation because of the milling force, a finite element model (FEM) of end milling process simulation in milling force field was established. On the base of FEM, we simulate the high-speed end milling type structure of aluminum alloy 7075 parts. We successfully predict the end milling force, obtain the effect between the upper and lower material to the milling force, and Mises stress and the tool length beyond the part.The simulation results show that the lower material can increase the milling force to upper, and upper material can decrease milling force to lower layer.The drilling tool length beyond the part is about 0.5 mm .

Computerized Optimization of the Process Parameters in Laser-Assisted Milling

Machining advanced materials, e.g. titanium alloys, usually results in a short tool life. Laser-assisted milling represents an innovative method to enhance machinability with less tool wear and an increased material removal rate. The material is heated locally and thereby softened before machining. This paper describes a thermo-mechanical simulation of a laser-assisted milling process in order to achieve a controlled heat impact. For that purpose the influence of different material parameters on the temperature field was analyzed computationally. The penetration depth of the laser induced heat and the thermally induced internal loads were investigated considering the loss of material and thus of heat during the milling process. Finally, the laser and the milling parameters were adapted for a real laser-assisted process.

Finite Element Analysis on the Roll Milling Process of Twisted Oblate Tube

The roll milling process for manufacturing a twisted oblate tube was presented and applied in the forming of twisted oblate copper tube successfully. A finite element simulation of the roll milling process for forming a twisted oblate 1010 steel tube was implemented on the basis of the elastic-plastic explicit dynamic finite element method under the ANSYS/LS-DYNA environment. The simulation accuracy was verified by comparing the forming force from simulation with the experimental results. The forming effect, change curve of forming force, tube stress distribution and influences of forming parameters on forming force were investigated. The simulation results can be guidance to the manufacturing process improvement and manufacturing equipment design of the twisted oblate steel tube.

Quadtree-array-based workpiece geometric representation on three-axis milling process simulation

A workpiece hybrid representation method based on quadtree-array is presented to improve the geometric simulation efficiency on three-axis milling process. The method takes the advantages both of Z-Map and quadtree in simulation model representation. The discrete points managed by using Z-Map algorithm is to represent the whole model, while the points used to represent the simulated surface detail are managed with quadtree-array. The method can reduce the levels of a quadtree without losing simulation accuracy. A dynamic optimization algorithm to the quadtree structure is highlighted to reduce its total nodes in simulation process. As a result, the simulation efficiency can be improved significantly. A three-axis milling process simulation system based on quadtree-array representation was developed and used to evaluate the performance of the presented method. The evaluated results show that quadtree-array-based hybrid representation method of workpiece can improve the simulation efficiency significantly, and reasonable division number of array cells is also recommended.