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 ◽  
◽  
...  

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.

2016 ◽  
Vol 2 (1) ◽  
Author(s):  
Christian Brecher ◽  
Marcel Fey ◽  
Matthias Daniels

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.


Author(s):  
Chia-Shin Yeh ◽  
Shang-Liang Chen ◽  
I-Ching Li

The core concept of smart manufacturing is based on digitization to construct intelligent production and management in the manufacturing process. By digitizing the production process and connecting all levels from product design to service, the purpose of improving manufacturing efficiency, reducing production cost, enhancing product quality, and optimizing user experience can be achieved. To digitize the manufacturing process, IoT technology will have to be introduced into the manufacturing process to collect and analyze process information. However, one of the most important problems in building the industrial IoT (IIoT) environment is that different industrial network protocols are used for different equipment in factories. Therefore, the information in the manufacturing process may not be easily exchanged and obtained. To solve the above problem, a smart factory network architecture based on MQTT (MQ Telemetry Transport), IoT communication protocol, is proposed in this study, to construct a heterogeneous interface communication bridge between the machine tool, embedded device Raspberry Pi, and website. Finally, the system architecture is implemented and imported into the factory, and a smart manufacturing information management system is developed. The edge computing module is set up beside a three-axis machine tool, and a human-machine interface is built for the user controlling and monitoring. Users can also monitor the system through the dynamically updating website at any time and any place. The function of real-time gesture recognition based on image technology is developed and built on the edge computing module. The gesture recognition results can be transmitted to the machine controller through MQTT, and the machine will execute the corresponding action according to different gestures to achieve human-robot collaboration. The MQTT transmission architecture developed here is validated by the given edge computing application. It can serve as the basis for the construction of the IIoT environment, assist the traditional manufacturing industry to prepare for digitization, and accelerate the practice of smart manufacturing.


Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2562
Author(s):  
Tomasz Dzitkowski ◽  
Andrzej Dymarek ◽  
Jerzy Margielewicz ◽  
Damian Gąska ◽  
Lukasz Orzech ◽  
...  

A method for selecting dynamic parameters and structures of drive systems using the synthesis algorithm is presented. The dynamic parameters of the system with six degrees of freedom, consisting of a power component (motor) and a two-speed gearbox, were determined, based on a formalized methodology. The required gearbox is to work in specific resonance zones, i.e., meet the required dynamic properties such as the required resonance frequencies. In the result of the tests, a series of parameters of the drive system, defining the required dynamic properties such as the resonance and anti-resonance frequencies were recorded. Mass moments of inertia of the wheels and elastic components, contained in the required structure of the driving system, were determined for the selected parameters obtained during the synthesis.


2015 ◽  
Vol 105 (06) ◽  
pp. 384-389
Author(s):  
E. Uhlmann ◽  
Y. Kuche ◽  
D. Oberschmidt ◽  
A. Löwenstein ◽  
S. Wiemann

Vorgestellt wird ein Maschinenprototyp zur Feinbearbeitung von Werkstückkanten und -oberflächen. Dieser verfügt über integrierte optische Messtechnik, die zur Kontrolle der Bearbeitungsergebnisse und gegebenenfalls zur automatisierten Nachbearbeitung eingesetzt werden kann. Mit dem Prototypen werden zum einen Fräswerkzeuge präpariert und zum anderen die Prozessparameter und deren Effekte analysiert. Abschließend beschreibt der Fachbeitrag einen Ansatz zur automatisierten Auslegung der Prozessparameter.   This paper presents a machine prototype for the finishing of edges and surfaces of work pieces. The prototype has an integrated optical measurement device, which can be used for the control of the process results and possibly automated remachining. The machine is used for the preparation of milling tools. Process parameters and their effects are analyzed and an approach for the automated setting of the process parameters is shown.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Smiljko Rudan ◽  
Irena Radić Rossi

Over the past decade, photogrammetric recording and virtual 3D modelling have evolved as a standard practice in documenting shipwreck sites. Exploiting the same methods, we can attempt to virtually reconstruct the dynamics of an accident leading to the creation of an archaeological site. By applying modern engineering tools capable of deploying multi-body system dynamics to simulate the damaging, capsizing and/or sinking of a ship, we can model and analyse the various possible scenarios of an incident occurring to an ancient merchantman. Subsequently, we can establish the correlation between the characteristics of the actual shipwreck site, and the outcome of the numerical simulation of the assumed scenario.


Metals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1825
Author(s):  
Haitham M. Ahmed ◽  
Hussin A. M. Ahmed ◽  
Mohammed Hefni ◽  
Essam B. Moustafa

In this investigation, aluminium Al-2.5% Mg cast alloy was modified by adding 0.5 Ti and 0.1 B wt % modifiers to investigate their impact on the dynamic behaviour, as well as the mechanical and microstructure properties. The dynamic properties were analysed experimentally using a free vibration impact test and predicted using finite element methods. This study used a high-resolution polarised optical microscope to analyse the microstructure of the studied alloys and X-ray Powder Diffraction (XRD) analysis to determine the developed phases. Microstructure and mechanical properties were mostly enhanced as a result of grain refining during solidification and through the metal segregation process. The microstructure analysis of the modified alloy showed a significant improvement in the grain refinement; hence, the grains were 10 times finer than the cast alloy. The modified Al-2.5% Mg/Ti-B alloy demonstrated reduced inter-granular corrosion (IGC) than the Al-2.5% Mg standard cast alloy. By incorporating Ti-B modifiers into the composition of the cast Al-Mg alloy, the ultimate tensile strength (UTS), strain (ε), and hardness values (HV) were increased by 30.5%, 100%, and 18.18%, respectively. The dynamic properties of the modified alloy showed an enhancement in the resonant (fn) and damping ratio (ζ) by 7% and 68%, respectively. The predicted resonance frequencies of the investigated alloys showed results close to the experimental dynamic tests.


2020 ◽  
Vol 17 (6) ◽  
pp. 1699-1716
Author(s):  
Jia-Qi Che ◽  
Han-Xiang Wang ◽  
Yan-Wen Zhang ◽  
Ming-Chao Du ◽  
Shao-Hua Ma

AbstractTo achieve the secondary production in multistage fracturing wells of tight oil, milling tools are usually used to remove the multistage fracturing ball seats to achieve production with a large diameter in later. In this paper, first of all, the working mechanism of milling tools for multistage fracturing ball seats was studied and a mechanical analysis model of single abrasive grain was established. Then, an experimental system for milling tools was developed, and the experimental tests of the flat, the blade, and the slope milling tool were conducted in order. Besides, the morphology of chips and the surface morphology of the workpiece after the experiment were analyzed. Also, the working performance of milling tools was evaluated from the perspectives of working safety, working efficiency, and wear resistance of the milling tool. The results show that the torque of the milling tool increases nonlinearly with the increase in the cutting depth of the abrasive grain and increases linearly with the increase in the cutting width. Also, the chips are irregular particles and the size is mainly from 10 to 50 μm. So, the chips should be pumped up with a small pump pressure and a large displacement. Besides this, the cutting depths of the abrasive grains are from 216.20 to 635.47 μm and the bottom surface of the milling tool should be eccentric to avoid the zero point of cutting speed. Furthermore, the torque of the slope milling tool is 23.8% larger than that of the flat milling tool, which is also 30.4% smaller than that of the blade milling tool. Compared with the flat milling tool, the working efficiency of the blade milling tool improves by 79.9% and the slope milling tool improves by 111.1%. Also, the wear resistance of the blade milling tool decreases by 102.7%, while the slope milling tool declines by 32.6% when compared with the flat milling tool. Therefore, the slope milling tool has the characteristics of moderate torque, stable working conditions, the highest working efficiency, and fine wear resistance, which is preferably used to mill multistage fracturing ball seats. This study provides a theoretical basis and guidance for milling multistage fracturing ball seats on-site and realizing production with a large diameter in later stages of multistage fracturing wells.


2011 ◽  
Vol 194-196 ◽  
pp. 1977-1981
Author(s):  
Dong Qiang Gao ◽  
Zhi Yun Mao ◽  
Zhong Yan Li ◽  
Fei Zhang

The modal analysis and harmonic response analysis of the machine tool table with periodic truss-core structures are analyzed and calculated by finite element analysis software-ANSYS Workbench, then we get the finite element analysis results. After comparing the results with finite element analysis results of the original machine tool table, we come to the conclusion that the dynamic properties of the machine tool table with periodic truss-core structures are better than the original machine tool table’s. It makes a base for optimized design and remanufacturing.


2016 ◽  
Vol 693 ◽  
pp. 906-913
Author(s):  
Kai Tao Xu ◽  
Bin Zou ◽  
Chuan Zhen Huang ◽  
Hui Jun Zhou ◽  
Han Lian Liu ◽  
...  

Micro milling is most flexible to create 3D features for application. However, how to design and fabrication of high precision micro milling tools are one of big challenges for mechanical micro milling. Commercially available micro milling tools are usually simply made from downsizing of macro milling tools, which have negative impact on milling performance. Therefore, in this paper, firstly, various structural of micro milling tools were optimized with abaqus that investigated stress and strain under certain static load on the cutting edges. Then, results showed the minimum stress and strain was a micro hexagonal end mill. Finally, a Ti (C7N3) cermet micro hexagonal end mill with a radius of 0.5mm was fabricated by wire electrical discharge machining, and the evaluation experiments for the hexagonal mill have been processed on a micro milling centre.


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