Effects of Structural Dynamics on Chatter in Machine Tools and Its Evaluation at Design Stage

1993 ◽  
pp. 501-519
Author(s):  
Mehmet S. Tekelioglu
Keyword(s):  
Structural Dynamics ◽  
Machine Tools ◽  
Design Stage

scholarly journals Optimisation of a Spindle Body Considering the Vibration Prediction of the Entire Milling Centre Construction

Mechanika ◽  
2021 ◽  
Vol 27 (1) ◽  
pp. 62-69
Author(s):  
Mateusz WĄSIK ◽  
Krzysztof LEHRICH ◽  
Krzysztof LIS
Keyword(s):  
Machine Tools ◽  
Dynamic Properties ◽  
The Body ◽  
Design Stage ◽  
Machining Parameters ◽  
Factors Affecting ◽  
Parametric Optimisation ◽  
Vibration Prediction ◽  
Ansys System ◽  
Spindle Body

Static and dynamic properties of machine tools have a decisive influence on their accuracy. In case of HSM machine tools, the phenomena associated with them are additionally strengthened by high machining parameters. In order to predict a machine tool behaviour at the design stage, it is necessary to use numerical methods to simulate for its simulation. Thanks to the use of this type of software, it is possible to perform the next step, i.e. the optimisation of the structure. In case of machine tools, due to the multiplicity of factors affecting its accuracy, this should be a multicriterial optimisation. This article presents the results of a vertical milling centre spindle body optimisation using the Finite Element Method. The results of static stiffness and vibration frequency analysis for three bodies (i.e. the body of the form and dimensions proposed by the constructor, the body after parametric optimisation and the body after the form and parametric optimisation including use of different materials) were compared. The optimisation tools available in the ANSYS system were used for the simulation. The calculations were preceded by experimental research and modifications of dynamic parameters performed on their basis using the author's methodology to determine the behaviour of a partially existing structure for different masses of the body being optimised.  

Dynamic error of multiaxis machine tools considering position dependent structural dynamics and axis coupling inertial forces

2021 ◽  
pp. 095440542110284
Author(s):  
Lei Yang ◽  
Xing Zhang ◽  
Lei Wang ◽  
Wanhua Zhao
Keyword(s):  
Structural Dynamics ◽  
Machine Tools ◽  
High Speed ◽  
Dynamic Error ◽  
Inertial Forces ◽  
Machining Performance ◽  
Working Process ◽  
Rigid Body Dynamic ◽  
Dynamic Errors ◽  
Gantry Machine Tool

During the working process of high-speed multiaxis machine tools, inertial forces can cause vibration and deformation of mechanical structure, which lead to the dynamic error of tool center point (TCP) relative to worktable and can adversely affect the machining performance. Considering the varying feed positions and accelerations during machining, a parameter-varying multi-rigid-body dynamic model of a 3-axis gantry machine tool is proposed. This model represents the position dependent structural dynamics and inertial forces, which can simulate the dynamic error of TCP relative to worktable within the entire workspace. The results show that the dynamic error in one direction is affected by the feed motions of multiple feed axes. The magnitudes of the dynamic error significantly vary with the position of Z-axis. And the dynamic errors in Y- and Z-direction show different varying trends. Then the theoretical model is used to discuss the dynamic error and position dependency. The expressions of TCP dynamic response and inertial forces reveal the reason why the dynamic errors in Y- and Z-direction show different varying trends.

Design for Manufacture Using a CAD/CAM System—A Methodology for Turned Parts

1983 ◽  
Vol 197 (3) ◽  
pp. 187-195 ◽  
Author(s):  
J C S Plummer ◽  
R G Hannam
Keyword(s):  
Design Process ◽  
Machine Tools ◽  
Software Package ◽  
Design Methodology ◽  
Raw Material ◽  
Design Stage ◽  
Design For Manufacture ◽  
System A ◽  
Cad Cam ◽  
Turned Parts

This paper describes a design methodology which has been developed to ensure that turned parts are designed for manufacture. The methodology has been incorporated in a software package which is used interactively on a CAD/CAM system. The methodology ensures that the choices offered to a designer during the design stage are such that turned parts can be produced to company standards using the manufacturing facilities available. The software package automatically selects the necessary raw material, the appropriate tool assemblies, and the necessary machine tools required to manufacture each component as its design process is carried out.

Improvements to Linear and Nonlinear Models of Machine Key Components

Impact ◽  
2021 ◽  
Vol 2021 (1) ◽  
pp. 15-17
Author(s):  
Yum Ji Chan
Keyword(s):  
Machine Tool ◽  
Virtual Machine ◽  
Structural Dynamics ◽  
Machine Tools ◽  
Dynamic Behaviour ◽  
Nonlinear Models ◽  
Wear And Tear ◽  
Linear And Nonlinear ◽  
Do So

Precision machinery has come a long way over the years. Factories that once relied on manpower now use machines, and this development has brought with it innumerable benefits including improvements to accuracy, repeatability, productivity and efficiency. Naturally, though, machines are imperfect in that precision of a batch of machines vary slightly. On top of that, machines experience wear and tear or even break-downs. These unpredictable events can be costly to manufacturers. This is why research to better understand factors that affect a machine's precision is important. This knowledge can be used to reduce the issues that occur with machine tools and thereby maximise the efficiency and quality of production. This is the goal of Dr Yum-Ji Chan, Department of Mechanical Engineering, National Chung Hsing University, Taiwan. His research on vibration engineering, structural dynamics and the dynamics of rotors is seeking to better understand machine tools and, in doing so, improve their performance. He believes more research is required to understand the behaviour of specific components in machine tools, and he is seeking to fill this gap in knowledge. This involves understanding the vibration phenomena that occur in components in machine tools and, to do so, Chan and his team are producing accurate dynamic behaviour in machine tool models. This will, in turn, enable researchers to develop virtual machine tools that can monitor the condition of machines.

Machine-Specific Estimation of Milling Energy Consumption in Detailed Design

2021 ◽  
pp. 1-24
Author(s):  
Till Boettjer ◽  
Johan Krogshave ◽  
Devarajan Ramanujan
Keyword(s):  
Energy Consumption ◽  
Machine Tool ◽  
Machine Tools ◽  
Design Stage ◽  
Total Energy Consumption ◽  
Estimation Errors ◽  
Workpiece Material ◽  
Detailed Design ◽  
Energy Estimation ◽  
Unit Process

Abstract Manufacturing is a significant contributor to global greenhouse gas emissions and there is an urgent need to reduce the energy consumption of production processes. An important step towards this goal is proactively estimating process energy consumption at the detailed design stage. This is a challenging task as variabilities in factors such as process specifications, machine tool architecture, and workpiece geometry can significantly reduce the accuracy of the estimated energy consumption. This paper discusses a methodology for machine-specific energy estimation in milling processes at the detailed design stage based on the unit process life cycle inventory (UPLCI) model. We develop an adjusted UPLCI model that includes adjustment factors for uncertainties in machine tool specifications and the specific cutting energy of a workpiece material. To validate the adjusted UPLCI model, we conducted a case study that measured the energy consumption for machining three parts made of Aluminum 6082 on two separate three-axis vertical milling machines, a Chevalier QP2040-L and a Leadwell MCV-OP. Results show that the UPLCI model consistently overestimated the total energy consumption for machining the three validation parts across both machine tools. We also found the adjusted UPLCI model significantly reduced the estimation errors for the same tests for both machine tools.

Dynamic Analysis of a Mesoscale Machine Tool

2005 ◽  
Vol 128 (1) ◽  
pp. 194-203 ◽  
Author(s):  
Sang Won Lee ◽  
Rhett Mayor ◽  
Jun Ni
Keyword(s):  
Dynamic Behavior ◽  
Structural Dynamics ◽  
Dynamic Characteristics ◽  
Machine Tools ◽  
Scaling Law ◽  
Milling Process ◽  
Lumped Parameter Model ◽  
Machining Performance ◽  
Significant Difference ◽  
Joint Dynamics

Miniaturized machine tools, referred to as mesoscale machine tools (mMTs) henceforth, have been proposed as a way to manufacture micro/mesoscale mechanical components. A thorough study of the dynamic behavior of the mMT is required for the successful development of its machine structure. This paper demonstrates the development of an mMT, the performance evaluation of its mesoscale milling process, and the characterization of its dynamic behavior. The mMT is developed by using an air turbine spindle and three piezoelectric linear stages, and its volumetric size is 150×70×140mm. A series of micro/mesoscale milling experiments are conducted, and the performances in the developed mMT testbed are evaluated. The dynamic characteristics of the mMT can be different from those of conventional machine tools because the mMT is a miniaturized structure and comprises different machine components. Therefore, the effect of the miniaturization of a structure on the change of its dynamic behavior, called scaling law of the structural dynamics, is studied numerically and experimentally. The dynamic characteristics of the developed mMT that are estimated from the scaling law of the structural dynamics are much different from those obtained from an experimental modal analysis, and the flexible joints of the developed mMT are mainly responsible for this significant difference. Therefore, the joint dynamics of the mMT are studied by introducing an equivalent lumped parameter model, thus enabling simple identification of the joint dynamics and the effective modification of its critical joints to enhance a machining performance.

scholarly journals Special Issue on Emerging Technology in Manufacturing

1997 ◽  
Vol 9 (6) ◽  
pp. 419-419
Author(s):  
Yoshimi Takeuchi ◽  
Keyword(s):  
Rapid Prototyping ◽  
Guest Editor ◽  
Machine Tools ◽  
Rapid Change ◽  
Emerging Technology ◽  
Manufacturing Technology ◽  
Design Stage ◽  
Ultra Precision ◽  
Nc Data ◽  
Manufacturing Technologies

Manufacturing yields value from worthlessness. Thus, in recent years, manufacturing technologies have been undergoing rapid change in order to produce products of high quality, at a low cost and with short lead times. Improvements and innovations, with regard to manufacturing technologies, range from the fundamentals to large-scale systems. Therefore, the guest editor would like to introduce the new manufacturing technology, together with the latest research results. One of the most recent key technologies is the so-called rapid-prototyping technology. It shortens the development period of new products from the design stage. Many rapid-prototyping technologies are being developed concurrently. In this issue, the state of the art is explained clearly by an expert in the field. For mechanical products, manufacturing capabilities are highly dependent upon machine tools. In this issue, there is a research paper concerned with a design method for multi-purpose machine tools that can fabricate a variety of products. Machining efficiency is strongly influenced by the positioning accuracy and feed velocity of the axis movement of the machine tools. A control algorithm that can achieve high speed and accuracy is proposed in a paper in this issue. In order to make the most of NC machine tools, it is essential to provide NC data rapidly However, it is difficult to generate NC data, especially for multi-axis control machine tools capable of machining workpieces with complicated shapes. The development of 6-axis control CAM software for creating sculpted surfaces is reviewed in the issue. Another paper deals with NC data generation for sculpted surface processing using virtual reality. In FA systems, the nature of the programming/execution environment is shifting from a concentrated one to a distributed one, and a worker-friendly manufacturing environment is required for the workers. Two papers are presented for realizing such environments. Recently, ultra-precision machining and micro-machining technologies have been attracting great interest as a result of their ability to produce micro-mechanisms and micro-robots. One paper describes production of a prototypical tiny part with a sculpted surface using an ultra-precision milling machine. Another is related to simulation of an atomic level cutting mechanism that applies molecular dynamics. Manufacturing technology is making tremendous progress, and is putting promising new technologies into use toward the goal of realizing intelligent manufacturing systems, IMS. The guest editor heartily hopes that this issue aids in comprehension of the emerging technology in the manufacturing field.

A new modularization method of heavy-duty machine tool for green remanufacturing

2018 ◽  
Vol 232 (23) ◽  
pp. 4237-4254 ◽  
Author(s):  
Qiang Cheng ◽  
Yiliang Guo ◽  
Zhifeng Liu ◽  
Guojun Zhang ◽  
Peihua Gu
Keyword(s):  
Machine Tool ◽  
Machine Tools ◽  
Clustering Algorithm ◽  
Design Stage ◽  
Design Parameters ◽  
Advanced Manufacturing ◽  
Heavy Duty ◽  
Atomic Theory ◽  
Structure Domain ◽  
The Ideal

The green remanufacturing constitutes a type of recycling form that adapts to ecological and economic requirements and an important part of the advanced manufacturing technology. In order to improve the green remanufacturing capacity of heavy-duty machine tools, in this paper a heavy-duty machine tool module division method for green remanufacturing was proposed. The main lines were based on the four design domains of axiomatic design and innovatively extended to the remanufacturing domain. In the design stage, the process of remanufacturing was considered. The modular clustering algorithm based on atomic theory was employed, which was associated with the correlation and similarity between the design parameters in the structure domain and the remanufacturing domain, for the ideal modules of heavy-duty machine tools to be discovered. Finally, a heavy-duty gantry milling machine is used as an example to verify the validity of the proposed method.

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