scholarly journals Modeling of Position-, Tool- and Workpiece-Dependent Milling Machine Dynamics

2016 ◽  
Vol 2 (1) ◽  
Author(s):  
Christian Brecher ◽  
Marcel Fey ◽  
Matthias Daniels
Keyword(s):  
Machine Tool ◽  
High Speed ◽  
Dynamic Properties ◽  
Major Effect ◽  
Modeling Framework ◽  
Milling Tool ◽  
Milling Machines ◽  
Engagement Process ◽  
Coupling Approach ◽  
Interpolation Strategy

AbstractDepending on the machine design, milling machines can show a significant variation of their dynamic properties with respect to the axes configurations, in particular at high speed spindle rotations and high feedrates. Moreover, the workpiece and the milling tool are critical parts of the machine tool and can have a major effect on the dynamic properties. Certain combinations of milling tool,workpiece, tool engagement, process parameters and axes configurations can come along with undesired forced or self-excited vibrations. So far, planning of milling processes usually does not account for these unwanted vibrations. The focus of this paper is to present a modeling framework, which accounts for the abovementioned influences via simulation. The dynamic properties of various workpieces and tools as well as the dynamic properties for many different axes configurations are stored in databases. Based on these databases, the dynamics of any given machine tool configuration can be simulated efficiently based on a substructure coupling approach and an interpolation strategy.

scholarly journals Adjustment of cutting modes based on the data of numerical simulation of a tool-workpiece system dynamics taking into account resonances

2020 ◽  
Vol 24 (5) ◽  
pp. 993-1006
Author(s):  
Pavel Kostin ◽  
◽  
Anatoly Lukyanov ◽  
Dmitry Aleinikov ◽  
◽  
...  
Keyword(s):  
Numerical Simulation ◽  
System Dynamics ◽  
Machine Tool ◽  
Manufacturing Process ◽  
Dynamic Properties ◽  
Electronic Catalog ◽  
Milling Tool ◽  
Resonance Frequencies ◽  
Milling Tools ◽  
Cutting Modes

The purpose of the work is to adjust the cutting modes for the manufacturing process of the Cover-Bracket part, which are set in accordance with the recommendations of the electronic catalog CoroPlus ToolGuide by the tool manufacturer Sandvik. This correction is required in order to improve the dynamic stability of machining. The problem of cutting mode adjustment is solved through the use of the methods of numerical simulation of the tool-workpiece system dynamics with regard to the resonances in the Femap engineering analysis program with Nastran. Recommendations are given for cutting modes taking into account the technical capabilities of the machine-tool and tooling, as well as the volume of the material removed with no reference for the dynamic properties of the tool and machine-tool. It is shown that at the 7th and 8th technological transitions the resonant vibrations are observed in the milling tool-workpiece system and the ratio of forces on the cutting edges of milling tools changes up to 245%, which leads to their uneven wear and decreases machining quality. It is found out that the oscillations of the processing forces can be represented as a sum of several harmonics of the rotational and tooth mesh frequencies. The results obtained show that the problem of deviation from the resonant frequencies can be solved not only by lowering the spindle speed, but also by changing the manufacturing process. Recommended change in the sequence of the technological transitions 7 and 8 allows to avoid resonance frequencies without reducing the performance level and machine at the maximum permissible cutter speed of 18,000 rpm. Under this approach, the first harmonics of the tooth mesh frequencies will be outside the resonant zone. In the future, it is planned to supplement the model with the dynamic characteristics of the machine-tool, tool and equipment.

Design of Damped Structures to Increase Machine Tool Dynamical Performance

2018 ◽  
Author(s):  
Francesco Aggogeri ◽  
Alberto Borboni ◽  
Angelo Merlo ◽  
Nicola Pellegrini ◽  
Riccardo Adamini ◽  
...  
Keyword(s):  
Machine Tool ◽  
Hybrid Materials ◽  
High Speed ◽  
Material Selection ◽  
Dynamic Properties ◽  
Structure Design ◽  
Machining Time ◽  
Reinforced Plastic ◽  
Innovative Materials ◽  
And Performance

The demand of ultra-high precision (UHP) machining is growing word-wide, driving the study and development of new solutions to increase the machine tool (MT) functionalities and performance. This trend has generated a request of smart, flexible and faster MTs that are able to reduce machining time and improve the final accuracy. The material selection in MT structure design and building may play a fundamental role to satisfy the customer’s requirements. In addition, the application of innovative materials in today’s technology may solve many issues that affect the machining quality due to static, dynamic and thermal behaviors. This paper presents a set of hybrid materials that may be used to fabricate the moving parts of a machine tool. The proposed solutions aim to guarantee lightness, capacity to damp vibrations and high stiffness limiting static and dynamic issues. The study focuses on four types of hybrid materials: sandwich structures based on Aluminium Foam, in open and closed cells configuration, sandwich panels with a corrugated core and Carbon Fiber Reinforced Plastic (CFRP) materials. A number of prototypes (milling MT ram – z axis) has been designed, manufactured and tested for high speed applications, evaluating both static and dynamic properties and highlighting potential advantages, drawbacks and new opportunities respect to conventional materials (e.g. iron, steel).

Composite Machine Tool Structures for High Speed Milling Machines

CIRP Annals ◽  
2002 ◽  
Vol 51 (1) ◽  
pp. 285-288 ◽  
Author(s):  
J.D. Suh ◽  
D.G. Lee ◽  
R. Kegg
Keyword(s):  
Machine Tool ◽  
High Speed ◽  
High Speed Milling ◽  
Milling Machines ◽  
Machine Tool Structures

scholarly journals Study of In-Situ Dynamic Balancing of Spindle- Chuck Assembly of CNC Lathe

2012 ◽  
pp. 11-15
Author(s):  
Vinay.V. N
Keyword(s):  
Machine Tool ◽  
High Speed ◽  
Dynamic Properties ◽  
Cnc Machine ◽  
Motorized Spindle ◽  
Spindle Shaft ◽  
Cnc Lathe ◽  
Machine Spindle ◽  
And Performance ◽  
Technology Level

The motorized spindle plays an important role in high-speed machining. The level and performance of CNC machine tool are decided and evaluated by a technology level of motorized spindle and its performance. Then it is necessary and significant to find efficient and convenient ways for the research of motorized spindle. The machine spindle system is one of the most important parts of a machine tool since its dynamic properties directly affect the cutting ability of the machine tool. The dimensions of the spindle shaft, location, stiffness of the bearings and bearing preload affect the vibration free operation of the spindle. Angular contact ball bearings are most commonly used in high-speed spindles due to their low-friction properties and ability to withstand external loads in both axial and radial directions.

scholarly journals NanoLEDs for energy-efficient and gigahertz-speed spike-based sub-λ neuromorphic nanophotonic computing

Nanophotonics ◽  
2020 ◽  
Vol 9 (13) ◽  
pp. 4149-4162 ◽  
Author(s):  
Bruno Romeira ◽  
José M. L. Figueiredo ◽  
Julien Javaloyes
Keyword(s):  
Neural Networks ◽  
Energy Efficient ◽  
High Speed ◽  
Dynamic Properties ◽  
Optical Computing ◽  
Differential Conductance ◽  
Rate Equations ◽  
Dynamical Equations ◽  
Electrical Modulation ◽  
High Bandwidth

AbstractEvent-activated biological-inspired subwavelength (sub-λ) photonic neural networks are of key importance for future energy-efficient and high-bandwidth artificial intelligence systems. However, a miniaturized light-emitting nanosource for spike-based operation of interest for neuromorphic optical computing is still lacking. In this work, we propose and theoretically analyze a novel nanoscale nanophotonic neuron circuit. It is formed by a quantum resonant tunneling (QRT) nanostructure monolithic integrated into a sub-λ metal-cavity nanolight-emitting diode (nanoLED). The resulting optical nanosource displays a negative differential conductance which controls the all-or-nothing optical spiking response of the nanoLED. Here we demonstrate efficient activation of the spiking response via high-speed nonlinear electrical modulation of the nanoLED. A model that combines the dynamical equations of the circuit which considers the nonlinear voltage-controlled current characteristic, and rate equations that takes into account the Purcell enhancement of the spontaneous emission, is used to provide a theoretical framework to investigate the optical spiking dynamic properties of the neuromorphic nanoLED. We show inhibitory- and excitatory-like optical spikes at multi-gigahertz speeds can be achieved upon receiving exceptionally low (sub-10 mV) synaptic-like electrical activation signals, lower than biological voltages of 100 mV, and with remarkably low energy consumption, in the range of 10–100 fJ per emitted spike. Importantly, the energy per spike is roughly constant and almost independent of the incoming modulating frequency signal, which is markedly different from conventional current modulation schemes. This method of spike generation in neuromorphic nanoLED devices paves the way for sub-λ incoherent neural elements for fast and efficient asynchronous neural computation in photonic spiking neural networks.

The Coupling Characteristic of HSK Tool-Holder/Spindle Interface for High-Speed NC Machine Tool

2014 ◽  
Vol 590 ◽  
pp. 121-125 ◽  
Author(s):  
Wen Kai Jie ◽  
Jian Chen ◽  
Deng Sheng Zheng ◽  
Gui Cheng Wang
Keyword(s):  
Machine Tool ◽  
Rotational Speed ◽  
High Speed ◽  
Nonlinear Finite Element Method ◽  
High Rotational Speed ◽  
Tool Holder ◽  
Nc Machine Tool ◽  
Machine Tool Accuracy ◽  
Nc Machine ◽  
Coupling Characteristic

The coupling characteristic of the tool-holder/spindle interface in high speed NC machine has significant influence on machine tool accuracy and process stability. With the example of HSK-E63, based on nonlinear finite element method (FEM), the coupling characteristic of the tool-holder/spindle interface under high rotational speed was investigated, the influence of interference, clamping force and rotational speed on the contact stress and the sectional area of clearance were discussed in detail. The results can be used as theoretical consideration to design and optimize the high speed tool-holder/spindle interface.

scholarly journals Novel analysis methods of dynamic properties for vehicle pantographs

2018 ◽  
Vol 180 ◽  
pp. 01005 ◽  
Author(s):  
Andrzej Wilk
Keyword(s):  
Dynamic Analysis ◽  
Dynamic Simulation ◽  
High Speed ◽  
Dynamic Properties ◽  
Equations Of Motion ◽  
Computer Software ◽  
Fem Analysis ◽  
Electrical Energy ◽  
Modern Approach ◽  
Static And Dynamic Analysis

Transmission of electrical energy from a catenary system to traction units must be safe and reliable especially for high speed trains. Modern pantographs have to meet these requirements. Pantographs are subjected to several forces acting on their structural elements. These forces come from pantograph drive, inertia forces, aerodynamic effects, vibration of traction units etc. Modern approach to static and dynamic analysis should take into account: mass distribution of particular parts, physical properties of used materials, kinematic joints character at mechanical nodes, nonlinear parameters of kinematic joints, defining different parametric waveforms of forces and torques, and numerical dynamic simulation coupled with FEM calculations. In this work methods for the formulation of the governing equations of motion are presented. Some of these methods are more suitable for automated computer implementation. The novel computer methods recommended for static and dynamic analysis of pantographs are presented. Possibilities of dynamic analysis using CAD and CAE computer software are described. Original results are also presented. Conclusions related to dynamic properties of pantographs are included. Chapter 2 presents the methods used for formulation of the equation of pantograph motion. Chapter 3 is devoted to modelling of forces in multibody systems. In chapter 4 the selected computer tools for dynamic analysis are described. Chapter 5 shows the possibility of FEM analysis coupled with dynamic simulation. In chapter 6 the summary of this work is presented.

scholarly journals Experimental and Numerical Analysis of High-Speed Internally Cooled Milling

CONVERTER ◽  
2021 ◽  
pp. 748-756
Author(s):  
Ningxia Yin Et al.
Keyword(s):  
High Speed ◽  
End Milling ◽  
Double Helix ◽  
Channel Structure ◽  
Dynamics Simulation ◽  
Thermal Dissipation ◽  
Machined Surface ◽  
Milling Tool ◽  
Internally Cooled ◽  
Cooling Technology

Advanced cooling technology is a crucial measure of thermal dissipation for high-speed end-milling. In order to get an appropriate cooling technology and decrease the negative effects of traditional wet cutting, internally cooled cutting has been paid more and more attention. Because of interrupted cutting and uneven force, there was few application and investigation on internally cooled end-milling. In the paper, the effect of the end-milling tool with different internally cooled channel structure has been researched by experiment and theoretical analysis. The experimental results indicate that the end-milling tool with double helix channels carried out best machined surface quality. And the experiment result was also been analyzed and explained by computational fluid dynamics simulation, which provides a basis for the applying of the high-speed internally cooled end-milling tool.

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