scholarly journals Research on Centroid Distribution and Dynamic Characteristics of Irregular Tooth End Milling Cutters

2021 ◽  
Vol 11 (21) ◽  
pp. 10071
Author(s):  
Haibin Yu ◽  
Minli Zheng ◽  
Wei Zhang ◽  
Wenrui Lv ◽  
Wanying Nie
Keyword(s):  
Dynamic Characteristics ◽  
Structural Design ◽  
Vibration Mode ◽  
End Milling ◽  
Dynamic Performance ◽  
Helix Angle ◽  
Element Analysis ◽  
Milling Cutter ◽  
Dynamic Excitation ◽  
Variable Helix

For irregular end milling cutters, the incomplete equality of the pitch angle and helix angle will lead to an uneven mass distribution. The problems of centroid distribution caused by this, and whether it would affect the dynamic characteristics of milling cutters, have not been systematically studied. In this paper, through the proposed mathematical model, the centroid positions of each radial section of four types of end milling cutters, with equal overall eccentricities and different structures, are calculated, respectively. The centroid distribution of end milling cutters is studied and analyzed. Combined with finite element analysis, the vibration mode, frequency, and resonance frequency band of each type of end milling cutter, under the same dynamic excitation, is obtained. Based on a study of the dynamic characteristics of various types of end milling cutters, it is found that the response displacement of the variable pitch variable helix end milling cutter is the smallest, which is 0.043800 mm. With the same level of accuracy, its dynamic performance is the best. On the premise of not changing the overall eccentricity of the end milling cutter, a new idea for the structural design to improve the dynamic characteristics of the end milling cutter is provided.

Dynamic Characteristics of a Micro-Sheet-Forming Machine System

2012 ◽  
Vol 504-506 ◽  
pp. 599-604 ◽  
Author(s):  
Yi Qin ◽  
Akhtar Razul Razali ◽  
Mei Zhou ◽  
Jie Zhao ◽  
Colin Harrison ◽  
...  
Keyword(s):  
Sheet Metal ◽  
Dynamic Characteristics ◽  
Dynamic Performance ◽  
Thin Sheet ◽  
Sheet Forming ◽  
Element Analysis ◽  
Machine System ◽  
Micro Parts ◽  
Thin Sheet Metal ◽  
Tooling System

Dynamic characteristics of a micro-forming machine system are of significant importance to be considered if high-precision micro-parts are to be produced. This is because forming tolerances may be within a range of sub-microns up to 5-15% of the thickness of a thin sheet-metal (e.g. <100µm) being used in micro-sheet-forming. Achievability of the quality parts often vary with the machine-system performance and process parameters being set, and it largely depends on the understanding of the machine and tool system’s dynamic characteristics and effectiveness of the control of the machine and the process. Nevertheless, there has been lack of the effort in this field of research. Significant number of the efforts in this field were focused mainly on discrete and/slow processes where the dynamic characteristics of the forming systems were often neglected. This paper presents the dynamic characteristics of an autonomous micro-sheet-forming machine system and its effect towards the produced parts’ quality. These have been studied by combining finite element analysis and forming experiment, with a particular focus on the combined effects from the machine, tooling system and the sheet-metal feeding system (the strip feeder). The results showed that, besides importance of the dynamic performance of the machine and the tool-system, dynamic characteristics of the material-feeding plays an important part in determining the parts’ quality produced.

Optimal design of helical flute of irregular tooth end milling cutter based on particle swarm optimization algorithm

2021 ◽  
pp. 095440622110420
Author(s):  
Haibin Yu ◽  
Minli Zheng ◽  
Wei Zhang ◽  
Wanying Nie ◽  
Tianchen Bian
Keyword(s):  
Particle Swarm Optimization ◽  
High Speed ◽  
End Milling ◽  
Dynamic Balance ◽  
Dynamic Performance ◽  
Particle Swarm ◽  
Curvature Radius ◽  
Swarm Optimization ◽  
Milling Cutter ◽  
Helical Flute

Due to the variable pitch angle and helix angle of the irregular tooth end milling cutter, the mass of the integral end milling cutter is eccentric, and the high stability and precision design of the irregular tooth end milling cutter is still a challenge. Aiming at the influence of dynamic balance of irregular tooth end milling cutter which can not be ignored in high-speed milling, the parameterized design of radial section of irregular tooth end milling cutter was carried out. Based on the space transformation law of the centroid of helical flute, a new method for calculating the centroid coordinate of end milling cutter was put forward, and a general mathematical model of eccentricity of integral end milling cutter was given. It was proved that this model could accurately calculate the centroid position and eccentricity of the end milling cutter. The influence of pitch difference angle and helix difference angle on eccentricity of end milling cutter was studied and analyzed. The particle swarm optimization (PSO) algorithm was creatively applied to optimize the helical flute shape of the end milling cutter, the curvature radius of helical flute curve is optimized, so that the centroid coordinate is infinitely close to the origin of coordinate. The number of iterations was set to 200. In the 32nd iteration, the result approached to infinitesimal, the final function converged, and obtained the groove curvature radius of the milling cuter with the smallest eccentricity. The optimized eccentricity of the end milling cutter is infinitesimal, which can make the vibration damping performance of the end milling cutter be fully developed. On the basis of ensuring the same cutting performance, the cutting tool unbalance was effectively reduced and the dynamic performance of milling cutter was further improved.

Identification Method of Dynamic Characteristics of Joints in Jointed Structures

2013 ◽  
Vol 7 (2) ◽  
pp. 221-227
Author(s):  
Shinji Shimizu ◽  
◽  
Yoshiaki Kabaya ◽  
Haruhisa Sakamoto ◽  
Kenichi Yamashita ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Transfer Function ◽  
Dynamic Characteristic ◽  
Dynamic Characteristics ◽  
Vibration Mode ◽  
Joint Model ◽  
Characteristic Parameters ◽  
Element Analysis ◽  
Spring Element

In this paper, we propose a method of identifying the dynamic characteristics of joints in jointed structures. We first consider a joint model for finite element analysis. We then propose, based on the consideration, a method of identifying dynamic characteristic parameters of the joint, such as the spring stiffness and damping coefficient, with the joint model. As a result, we obtain a joint model with the spring and damping elements in vertical and tangential directions between a pair of nodes with changeable numbers and locations. The number and location of these elements can be determined so that the vibration mode and the inertance transfer function of the jointed structure obtained from finite element analysis with infinite stiffness of the spring element agree with those of the structure without joints. In addition, we identify the dynamic characteristic parameters of the joint so the experimental inertance transfer function and vibration mode agree with those obtained from the finite element analysis.

scholarly journals Design and Optimization of Micromilling Cutting Tools

2018 ◽  
Vol 220 ◽  
pp. 04003
Author(s):  
Ikhsan Siregar ◽  
Juri Bin Saedon ◽  
Mohd Shariman Adenan
Keyword(s):  
End Milling ◽  
Cutting Tools ◽  
Helix Angle ◽  
Maximum Principal Stress ◽  
Micro Milling ◽  
Tool Geometry ◽  
Element Analysis ◽  
Design And Optimization ◽  
Micro Parts ◽  
Micro End Milling

With the trend towards miniaturization, micromachining become more and more important in fabricating micro parts. The micromachining process that involved in this study is micro milling. The focus of the study is on the comparison performance between various numbers of flutes (4-flutes, 6-flutes and 8-flutes) with various helix angle (25º,30º and 35º) in micro end milling tool geometry with the conventional micro end milling, 2-flutes micro end milling. Cemented carbide is the material that been used for this study. The main problem about the two flutes micro end milling is it easily wears in a short time. In this study, finite element analysis of the model using cantilever beam principle theory. The tools will be modelled and simulate using Abaqus/CAE 6.10. The tool performance of the designed tool will be evaluated by using the maximum principal stress, σ_max. According to the analysis, weakest geometry is 2-flutes micro end milling and the strongest is 8-flutes micro end milling. 8-flutes micro end milling can be the option to replace the conventional micro end milling.

Analysis on the Influencing Factors of Dynamic Characteristics for the Linear Motion Station of DCG

2013 ◽  
Vol 437 ◽  
pp. 194-197
Author(s):  
Xiao Peng Li ◽  
Xing Ju ◽  
Guang Hui Zhao ◽  
Ya Min Liang ◽  
Hao Tian Yang
Keyword(s):  
Dynamic Characteristics ◽  
High Speed ◽  
Dynamic Performance ◽  
Cnc Machine Tools ◽  
Joint Surface ◽  
Design Parameters ◽  
Machining Accuracy ◽  
Cnc Machine ◽  
Element Analysis ◽  
Feed Drive

Dynamic characteristics of the system have been given more and more attention so as to improve the retention and reliability of machining accuracy. Research has shown that dynamic performance of the feed drive mechanism has significant impact on the processing quality and efficiency of CNC. This paper mainly focuses on the DCG which realizes its motion on the basis of a pair of lead screw. The dynamic performance of the DCG was analyzed by the method of finite element analysis. DCG structure and the key design parameters of the rail joint surface have been studied to find out the influence on its dynamic characteristics. These researches provided a basis for the realization of the CNC feed motion of high-speed and high-precision. Besides, it is also possible to improve the overall performance of CNC machine tools.

Anticipation of Stability Limits for Two Degree-of-Freedom Interrupted Milling

2009 ◽  
Vol 25 (1) ◽  
pp. 41-48
Author(s):  
B. M. Imani ◽  
M. H. Sadeghi ◽  
M. Kazemi
Keyword(s):  
Cutting Force ◽  
End Milling ◽  
Experimental Tests ◽  
Helix Angle ◽  
Vibratory System ◽  
Element Analysis ◽  
Stability Behavior ◽  
Milling Operations ◽  
The Stability ◽  
Low Radial Immersion

AbstractMilling is becoming an increasingly universal machining operation for producing parts used in aerospace, automotive, and life science engineering industries. The characteristics common to such parts are a high level of complexity and structural flexibility, both of which usually necessitate using low radial immersion milling operations. Low radial immersion milling operations involve interrupted cutting which induces chatter vibration under certain cutting conditions. The stability behavior of low immersion helical end milling processes is investigated in this paper. Time Finite Element Analysis (TFEA) is suggested for an approximate solution for delayed differential equations encountered during interrupted milling. An improved TFEA is proposed which includes the effects of helix angle variations on cutting force, cutting time and specific cutting force coefficients for a 2 DOF vibratory system. To verify the proposed method, experimental tests have been conducted which prove that the improved TFEA method accurately predicts the stability behavior of low immersion milling.

Modal Analysis of Scraper Chain Industrial Robot System

2014 ◽  
Vol 490-491 ◽  
pp. 1190-1193
Author(s):  
Na Liu ◽  
Dian Long Zou ◽  
Tian Jiao Zhou ◽  
Jian Wei Zhao
Keyword(s):  
Finite Element ◽  
Modal Analysis ◽  
Dynamic Characteristics ◽  
Vibration Mode ◽  
Industrial Robot ◽  
Three Dimensional ◽  
Three Dimensional Model ◽  
Element Analysis ◽  
Rail Line ◽  
Inherent Frequency

This paper researched dynamic characteristics of 5-DOF scraper chain handling robot by finite element modal analysis. Firstly established the whole three-dimensional model with Solidworks, secondly, transferred it into the ANSYS finite element analysis software to analyze dynamic characteristics in two fixed work positions when it was grasping a scraper chain and carrying a scraper chain on a rail line. It was found the weak component which vibrated heavily was the big arm from the analysis of the top 5 order vibration mode. Then studied modal analysis of the big arm to obtain the its inherent frequency and vibration mode. Finally put forward some suggestions about the design of the handling robot and improved its dynamic characteristics which is meaningful to increase its stability and reliability.

Structure Optimization of the Aluminum Alloy Frames of Flight Simulator

2015 ◽  
Vol 667 ◽  
pp. 582-587
Author(s):  
Jun Liu ◽  
Pu Guo Gui ◽  
Jian Mei Wang ◽  
Yang Yu ◽  
Zheng Hu Zhong
Keyword(s):  
Aluminum Alloy ◽  
Dynamic Characteristics ◽  
Dynamic Performance ◽  
Synthesis Method ◽  
Frame Structure ◽  
Cast Aluminum Alloy ◽  
Cast Aluminum ◽  
Element Analysis ◽  
Motion Simulator ◽  
Rotating Load

Frames are the main components of the flight motion simulator, which are the support for each shaft system, at the same time the rotating load for the external shaft, so the stiffness and dynamic characteristics of the frames in a large extent determines the final accuracy and dynamic performance of the flight motion simulator. For the cast aluminum alloy ZL114A frames of a 3-DOF flight motion simulator, using finite element analysis method, the dynamic characteristics are calculated and analyzed, and then the each order resonance frequency and mode of vibration are obtained. By using of the modal synthesis method and optimization algorithms, the structural dynamics of frames are designed optimally, so as to further reducing the moment of inertia, and improving the stiffness and dynamic characteristics of frames. This method has provided important reference for the reasonable design of the frame structure, and definitively established the foundation to further study the triaxial coupling dynamic characteristics and system mechanical optimization for the flight motion simulator.

Robust design of a novel three-axis fine stage for precision positioning in lithography

2010 ◽  
Vol 224 (4) ◽  
pp. 877-888 ◽  
Author(s):  
D-J Lee ◽  
K Kim ◽  
K-N Lee ◽  
H G Choi ◽  
N-C Park ◽  
...  
Keyword(s):  
Dynamic Characteristics ◽  
Structural Design ◽  
Magnetic Circuit ◽  
Magnetic Coupling ◽  
Access Time ◽  
Precision Positioning ◽  
Element Analysis ◽  
High Bandwidth ◽  
Dual Stage ◽  
Fast Access

The precision positioning system for semiconductor lithography requires a robust structural design to obtain enough control bandwidth and an efficient actuator with fast access time. In this article, a three-axis stage is proposed as a fine stage of a dual stage for the precision positioning. Its actuators are voice coil motors (VCMs) whose coil windings are mounted on the coarse stage and its magnets are on the fine stage. Between the fine and coarse stages, there is no mechanical connection but only magnetic coupling. The eight pairs of magnets and four coil windings are arrayed symmetrically. The three-axis stage's dynamic characteristics are improved by enhancing the actuating force and modifying its own structure using finite-element analysis in order to meet its requirements of high bandwidth and large forces. The actuating force is strengthened by modifying each VCM's magnetic circuit. The structure is designed to be robust by using design of experiment (DOE) as well. The modified stage is verified to have enough dynamic characteristics through experiments.

scholarly journals Simulation Research on Dynamic Characteristics of Hydraulic Mount

2021 ◽  
Vol 34 (1) ◽  
Author(s):  
Yanhua Liu ◽  
Xin Guan ◽  
Pingping Lu ◽  
Rui Guo
Keyword(s):  
Dynamic Characteristics ◽  
Mechanical Model ◽  
Structural Parameters ◽  
Dynamic Stiffness ◽  
Dynamic Performance ◽  
Evaluation Index ◽  
Loss Angle ◽  
Element Analysis ◽  
Nonlinear Mechanical ◽  
Performance Evaluation Index

AbstractAt present, research on hydraulic mounts has mainly focused on the prediction of the dynamic stiffness and loss angle. Compared to the traditional finite element analysis method, the programming method can be used to analyze hydraulic mounts for a rapid and accurate understanding of the influence of the different mounting parameters on the dynamic stiffness and loss angle. The aims of this study were to investigate the nonlinear dynamic characteristics of a hydraulic mount, and to identify the parameters that affect the dynamic stiffness and loss angle using MATLAB software programs to obtain the influence curves of the parameters, so as to use suitable parameters as the basis for vibration analysis. A nonlinear mechanical model of a hydraulic mount was established according to the basic principles of fluid dynamics. The dynamic stiffness and loss angle of the dimensionless expression were proposed. A numerical calculation method for the dynamic performance evaluation index of the hydraulic mount was derived. A one-to-one correspondence was established between the structural parameters and peak frequency of the evaluation index. The accuracy and applicability of the mechanical model were verified by the test results. The results demonstrated the accuracy of the nonlinear mechanical model of the hydraulic mount, and the vehicle driving comfort was greatly improved by the optimization of the structural parameters.

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