scholarly journals Digital simulation cylindrical milling process with end mills

2021 ◽  
Author(s):  
Yurii Petrakov ◽  
Maksym Sikailo
Keyword(s):  
Degrees Of Freedom ◽  
Block Diagram ◽  
Digital Simulation ◽  
Numerical Algorithms ◽  
Research Process ◽  
Milling Process ◽  
Cutting Process ◽  
Mass Model ◽  
Delay Argument ◽  
Machining System

Any cutting process is accompanied by vibrations that can lead to a chatter of machining surface and even to a loss of stability. Mathematical modeling helps to solve such problems of the choice of cutting mode that provide vibration-free machining. The developed mathematical model takes into account the closed of the cutting process and machining "on the trail", which is implemented in its structural diagram representing the process, feedbacks and a function of a delay argument. The dynamic model of a technological machining system is represented by a single-mass model with two degrees of freedom. The developed block diagram of the system together with numerical algorithms for solving the geometric intersection of the cutter tooth with the workpiece and the numerical method of integrating differential equations form the basis of the created application program for digital modeling of the process. The simulation results indicate an adequate response of the program as a whole, which allows us to take the proposed methodology as the basis for further improvement of the virtual research process and the prediction of its real properties. Key words: Cylindrical milling, end mill, digital simulation.

Mechanism of Variable Helix Tools in Suppressing Chatter Using Process Damping for Machining Titanium Alloys at Low Cutting Speed

2013 ◽  
Vol 773-774 ◽  
pp. 370-376
Author(s):  
Muhammad Adib Shaharun ◽  
Ahmad Razlan Yusoff ◽  
Mohammad S. Reza
Keyword(s):  
Titanium Alloy ◽  
Cutting Speed ◽  
Milling Process ◽  
Cutting Process ◽  
Chatter Vibration ◽  
Process Damping ◽  
High Cutting Speed ◽  
Titanium Machining ◽  
Different Types ◽  
Variable Helix

Titanium is difficult-to-cut materials due to its poor machinability and thermal conductivity when machining at high cutting speed. To overcome this machining titanium alloy problem, this study in interaction between machining structural system and the cutting process are very important. One of the main problems in the cutting process is chatter vibration. Due to chatter problem, the mechanism to suppress chatter named, process damping is a useful method can be manipulated to improve the limited productivity of titanium machining at low speed machining in milling process. In the present study, experiment are conducted to evaluate and study the process damping mechanism in milling using different types of variable tools geometries. These tools are variable he-lix/uniform pitch, variable pitch/uniform helix and variable helix and pitch and uniform helix/pitch. The result showed that the variable helix and pitch tools is very significantly improve process damping performance in machining titanium alloy compare to traditional of regular tools and other irregular tools.

Study on the Cutting Temperature and Chips Formation during the Milling of Pure Titanium

2018 ◽  
Vol 880 ◽  
pp. 315-320
Author(s):  
Emil Nicusor Patru ◽  
Dumitru Panduru ◽  
Nicolae Craciunoiu ◽  
Marin Bica
Keyword(s):  
Pure Titanium ◽  
Cutting Temperature ◽  
Milling Process ◽  
Cutting Conditions ◽  
Cutting Process ◽  
Screen Capture

In this paper some experimental determinations on the temperature during the milling process of pure titanium is conducted, using different cutting conditions. The results are presented as graphical dependencies and also as a screen capture of the values obtained using an adequate technique for temperature of the cutting process. Some pictures of the chips shape captured during milling process of the pure titanium bare are presented.

The Evaluation of the up and down Milling Based on its Chip

2014 ◽  
Vol 941-944 ◽  
pp. 1943-1946
Author(s):  
Jozef Zajac ◽  
Veronika Fečová ◽  
Peter Michalik ◽  
Marek Kočiško ◽  
Jan Zajac ◽  
...  
Keyword(s):  
Milling Process ◽  
Cutting Process ◽  
Economical Aspect

The main aim of this contribution was monitoring of chip in the milling process by the evaluation of the volumetric coefficient of chip. The chip was monitoring during the peripheral up and down milling. Nowadays, the milling is the most used technology in engineering. The shape of chip is important for its transport and for economical aspect of this technology. This coefficient represents the shape of chip. The small chip has a lower volumetric coefficient, but the very small chip is not very desired in the cutting process, because they can fill some small spaces and damage the machine. But very long chip can damage tool and machine, too.

scholarly journals VIRTUAL LABORATORIES AS STRATEGY FOR TEACHING IMPROVEMENT IN MATH SCIENCES AND ENGINEERING IN BOLIVIA

2020 ◽  
Vol 2 (1) ◽  
pp. 52-62
Author(s):  
Francisco Vargas
Keyword(s):  
Differential Equations ◽  
Matrix Algebra ◽  
Degrees Of Freedom ◽  
Inverted Pendulum ◽  
Numerical Algorithms ◽  
Three Dimensions ◽  
Technological Advancement ◽  
Teaching Improvement ◽  
Two Degrees Of Freedom ◽  
Virtual Laboratories

The vertiginous technological advancement has made necessary the use of computersoftware that contributes to the improvement of teaching in math sciences and engineering.It is in this context that the last five years the strategy presented in this article has been disseminatedin the main universities of Bolivia, a country where the schools have not yet been ableto offer basic disciplines such as calculus, matrix algebra, physics and/or differential equationsto solve problems considering applicative aspects. To establish this connection, it is necessaryto deduce differential equations associated with practical problems, solve these equationswith different numerical algorithms, and establish the concept of simulation to later introducelanguages like Python/VPython free of license to elaborate Virtual Laboratories that allow obtainingthe solutions in two and three dimensions. The classical problems addressed for thispurpose are the satellite of two degrees of freedom and the inverted pendulum.

Modal Simulation and Testing of a Micro-Manipulator

2004 ◽  
Vol 127 (3) ◽  
pp. 515-519 ◽  
Author(s):  
Yongjun Lai ◽  
Marek Kujath ◽  
Ted Hubbard
Keyword(s):  
Numerical Simulations ◽  
Degrees Of Freedom ◽  
Compliant Mechanism ◽  
Dynamic Properties ◽  
Experimental Results ◽  
Mass Model ◽  
Thermal Actuators ◽  
Micro Manipulator ◽  
Six Dof

A micro-machined manipulator with three kinematic degrees-of-freedom (DOF): x, y, and φ is presented. The manipulator is driven by three thermal actuators. A six DOF discrete spring-mass model of the compliant mechanism is developed which manifests the dynamic properties of the device. Numerical simulations are compared with experimental results.

Geometric Modeling of Cutter/Workpiece Engagements in 3-Axis Milling Using Polyhedral Models

2007 ◽  
Author(s):  
Eyyup Aras ◽  
Derek Yip-Hoi
Keyword(s):  
Cutting Forces ◽  
Geometric Modeling ◽  
Tool Path ◽  
Cutting Tool ◽  
Milling Process ◽  
Mapping Technique ◽  
Depth Of Cut ◽  
Modeling Methodology ◽  
Machining System ◽  
Engagement Angle

Modeling the milling process requires cutter/workpiece engagement (CWE) geometry in order to predict cutting forces. The calculation of these engagements is challenging due to the complicated and changing intersection geometry that occurs between the cutter and the in-process workpiece. This geometry defines the instantaneous intersection boundary between the cutting tool and the in-process workpiece at each location along a tool path. This paper presents components of a robust and efficient geometric modeling methodology for finding CWEs generated during 3-axis machining of surfaces using a range of different types of cutting tool geometries. A mapping technique has been developed that transforms a polyhedral model of the removal volume from Euclidean space to a parametric space defined by location along the tool path, engagement angle and the depth-of-cut. As a result, intersection operations are reduced to first order plane-plane intersections. This approach reduces the complexity of the cutter/workpiece intersections and also eliminates robustness problems found in standard polyhedral modeling and improves accuracy over the Z-buffer technique. The CWEs extracted from this method are used as input to a force prediction model that determines the cutting forces experienced during the milling operation. The reported method has been implemented and tested using a combination of commercial applications. This paper highlights ongoing collaborative research into developing a Virtual Machining System.

First-Crossing Problem of Weakly Coupled Strongly Nonlinear Oscillators Subject to a Weak Harmonic Excitation and Gaussian White Noises

2018 ◽  
Vol 140 (4) ◽  
Author(s):  
Y. J. Wu ◽  
H. Y. Wang
Keyword(s):  
Harmonic Function ◽  
Degrees Of Freedom ◽  
High Efficiency ◽  
Digital Simulation ◽  
Stochastic Averaging ◽  
Harmonic Excitation ◽  
Van Der Pol Oscillator ◽  
Strongly Nonlinear ◽  
Set Up ◽  
White Noises

We study first-crossing problem of two-degrees-of-freedom (2DOF) strongly nonlinear mechanical oscillators analytically. The excitation is the combination of a deterministic harmonic function and Gaussian white noises (GWNs). The generalized harmonic function is used to approximate the solutions of the original equations. Four cases are studied in terms of the types of resonance (internal or external or both). For each case, the method of stochastic averaging is used and the stochastically averaged Itô equations are obtained. A backward Kolmogorov (BK) equation is set up to yield the failure probability and a Pontryagin equation is set up to yield average first-crossing time (AFCT). A 2DOF Duffing-van der Pol oscillator is chosen as an illustrative example to demonstrate the effectiveness of the analytical method. Numerically analytical solutions are obtained and validated by digital simulation. It is shown that the proposed method has high efficiency while still maintaining satisfactory accuracy.

Multiscale Control to Meet the Conflicting Nanoscale Performance Requirements

2005 ◽  
Author(s):  
Huzefa Shakir ◽  
Won-Jong Kim
Keyword(s):  
Degrees Of Freedom ◽  
Reference Model ◽  
Control Strategies ◽  
Mass Model ◽  
Integral Term ◽  
Six Degrees Of Freedom ◽  
Performance Requirements ◽  
Model Following ◽  
Control Schemes ◽  
Domain Performance

In this paper, we consider the problem of designing a multiscale control for plants with conflicting time-domain performance requirements. These results follow from the conventional optimal proportional-integral (PI) control. Four different design methods are proposed: (1) a controller-switch technique which makes use of employing two different controllers designed to meet two different performances and are switched during the course of operation, (2) an integral-reset scheme, which resets the integral term in the control law when the new reference point is reached, (3) controller-switch and integral-reset schemes put together to take benefits of both of them, (4) a model-following approach that uses a dynamic reference model without increasing the overall dimension of the system. The objective of the last scheme is to make the output of the plant track the output of the model as closely as possible. Stability analyses and a comparison between the performances of these methods are given. All these methods give better performances as compared with conventional control schemes. Block diagrams are given and step responses are obtained to demonstrate the proposed methods. A six degrees-of-freedom (DOFs) magnetically levitated (maglev) stage with a second-order pure-mass model has been used to demonstrate the capabilities of the aforementioned control strategies. These strategies are not plant-specific and may be generalized to any higher-order plant.

Measurement and Modeling of Heat Partitions and Temperature Fields in the Workpiece for Cutting Inconel 718, AISI 1045, Ti6Al4V, and AlMgSi0.5

2019 ◽  
Vol 141 (6) ◽  
Author(s):  
Thorsten Augspurger ◽  
Thomas Bergs ◽  
Benjamin Döbbeler
Keyword(s):  
Heat Flow ◽  
Peclet Number ◽  
Inconel 718 ◽  
Flow Distribution ◽  
Milling Process ◽  
Cutting Process ◽  
Evaluation Criterion ◽  
Temperature Fields ◽  
Péclet Number ◽  
Aisi 1045

The quantification of the heat flow distribution in the metal cutting process depending on the cut material and the process parameters is a research area with a long history. However, a quantification of the heat flow distribution between chip, tool, and workpiece is still a not fully solved problem and remains a necessary input value for the further modeling of temperature fields and subsequent tool wear and thermal induced surface alterations, which may impair the workpiece functionality. Thus, the following publication shows the results of orthogonal cutting in order to investigate the heat flow distribution between the chip and workpiece. Therefore, the heat partitions in the cutting process were calculated by a thermodynamic methodology. This methodology considers the temperature rise in the workpiece and the chip, measured by thermography and pyrometry, as the effect of the cutting work dissipated into sensible heat. Four metals, Inconel 718, AISI 1045, Ti6Al4V, and AlMgSi0.5, were cut at varying undeformed chip thicknesses and cutting velocities. By formulating a dimensionless number for the cutting process, the Péclet number, the thermal diffusivity was included as an evaluation criterion of heat partitioning between the chip and workpiece across material properties and process settings. In this way, the validity of the Péclet number as an evaluation criterion for heat partitions in cutting and as a valuable heuristic for process design was confirmed. Another goal was to extend the state of the art approach of empirical process analysis by orthogonal cuts with regard to specific cutting forces into the thermal domain in order to provide the basis for further temperature modeling in cutting processes. The usage of the empirical data basis was finally demonstrated for the analytical modeling of temperature fields in the workpiece during milling. Therefore, the specific heat inputs into the workpiece measured in the orthogonal cuts were transferred to the milling process kinematics in order to model the heat flow into the workpiece during milling. This heat flow was used as input for an existing analytical model in order to predict stationary temperature fields in the milling process for the two-dimensional case.

Design and Characterization of a Magnetorheological Damper for Vibration Mitigation during Milling of Thin Components

2016 ◽  
Vol 1812 ◽  
pp. 65-70 ◽  
Author(s):  
S. Puma-Araujo ◽  
D. Olvera-Trejo ◽  
A. Elías-Zuñiga ◽  
O. Martínez-Romero ◽  
C.A. Rodríguez
Keyword(s):  
Degrees Of Freedom ◽  
End Milling ◽  
Experimental Tests ◽  
Milling Process ◽  
Magnetorheological Damper ◽  
Machining Process ◽  
Manufacturing Cost ◽  
Thin Wall ◽  
Integration Model

ABSTRACTThe aerospace and automotive industries demand the development of new manufacturing processes. The productivity during machining of very flexible aerospace and automotive aluminum components is limited for self-excited vibrations. New solutions are needed to suppress vibrations that affect the accuracy and quality of the machined surfaces. Rejection of one piece implies an increase in the manufacturing cost and time. This paper is focused on the design, manufacturing and characterization of a magnetorheological damper. The damper was attached to a thin-floored component and a magnetic field was controlled in order to modify the damping behavior of the system. The dynamics of the machining process was developed by considering a three-degree-of-freedom model. This study was experimentally validated with a bull-nose end milling tool to manufacture monolithic parts with thin wall and thin floor. Experimental tests and characterization of the magnetorheological damper permitted to improve the surface finish and productivity during the machining of thin-floored components. A further aim of this paper was to develop a rheological damper by using magnetorheological fluids (MR) to change the thin floor rigidity with voltage. The stability of the milling process was also analytically described considering one, two or three degrees of freedom, using a mathematical integration model based on the Enhanced Multistage Homotopy Perturbation Method (EMHPM).

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