scholarly journals Advances in the dynamic characteristics of high -speed machine structure

2017 ◽  
Vol 20 (K5) ◽  
pp. 73-80
Author(s):  
Loc Huu Nguyen ◽  
Thuy Van Tran
Keyword(s):  
Natural Frequency ◽  
Dynamic Characteristics ◽  
High Speed ◽  
Machining Process ◽  
Vibration Resistance ◽  
Operating Process ◽  
Processed Products ◽  
Machine Structure ◽  
Selection Of

The quality of machining is dependent on the machine’s dynamic behavior throughout the operating process. Because of the loads or vibration during operation, the rigidity of the machine structure can be reduced. Therefore, the study of advances in the dynamic characteristics has great significance for the development of machine tools, especially for high-speed machines. This paper presents the design and analysis of a rigid gantry structure with a spindle speed in the range of (6.000 ÷ 24.000)rpm, corresponding to the natural frequency of the machine structure more than (100 ÷ 400)Hz. Use CAE (computer-aided engineering) analysis software to analyze the natural frequency of machine structure. The research results show that the machine structure will have good stiffness, high vibration resistance and avoid resonance to achieve the best machining surface. In addition, it is the basis for selection of cutting mode suitable for the machining process in order to improve the reliability and efficiency of work of the machine structure and the accuracy of the processed products.

Application of Experimental Modal Analysis Method in Researching of Mechanical Structure Dynamic Characteristics

2013 ◽  
Vol 694-697 ◽  
pp. 370-373
Author(s):  
Zhang Yu ◽  
Wen Zheng Cai
Keyword(s):  
Modal Analysis ◽  
Natural Frequency ◽  
Dynamic Characteristics ◽  
High Speed ◽  
Experimental Modal Analysis ◽  
Analysis Method ◽  
Mechanical Structure ◽  
Vibration Resistance ◽  
Structural Rigidity ◽  
Structure Dynamic

With the purpose of realizing the analysis of mechanical structure dynamic characteristics and inhibit vibration and noise, combined with the analysis of a certain type of high speed sewing machines vibration characteristics, we carry on the concrete experimental modal analysis, and compare the results of the experimental modal analysis with the results of spectrum analysis. The analysis results show that the second order natural frequency of the shell is close to two octaves under the normal working speed of sewing machine and it will lead to resonance. Enhancing the structural rigidity and the natural frequency under this modal to avoid resonance frequency is the key to improve vibration resistance of the structure.

scholarly journals Technical parameters of high speed lines as the determinant for selection of rolling stock

2018 ◽  
Vol 180 ◽  
pp. 06007
Author(s):  
Jan Raczyński
Keyword(s):  
High Speed ◽  
Point Of View ◽  
Rolling Stock ◽  
High Speed Rail ◽  
Technical Parameters ◽  
Rail Vehicle ◽  
Railway Infrastructure ◽  
The One ◽  
Selection Of

Choosing a high-speed rail vehicle depends on many factors. On the one hand, there are requirements for ensuring the quality of service for passengers, on the other hand, there are constraints resulting from the parameters of available infrastructure. Also a relation of the benefit and financial costs associated with the purchase and the operation of rolling stock is essential. Technical characteristics of vehicles selected for operating a particular system is a compromise between the three groups of requirements. In this article technical parameters of railway infrastructure and rolling stock are classified and then analysed from the TSI requirements point of view.

Vibration Analysis of Radial Drilling Machine Structure Using Finite Element Method

2012 ◽  
Vol 472-475 ◽  
pp. 2717-2721 ◽  
Author(s):  
Rajiv Kumar ◽  
Mohinder Pal Garg ◽  
Rakesh C. Sharma
Keyword(s):  
Machine Tool ◽  
Natural Frequency ◽  
Mode Shapes ◽  
Drilling Machine ◽  
Element Analysis ◽  
Stiffness Matrices ◽  
Machine Tool Structure ◽  
Radial Drilling ◽  
Machine Structure

Manufacturing industries now a days have stringent expectation from the machine tools in terms of productivity as well as quality of products.Vibration plays an important role in determining the quality of product.If the pattern of vibration prevailing in the machine tool during cutting is known,then machine tool structure can be designed in such a way so that natural frequency of machine tool structure can be isolated from the forced frequency.So, this study is focused on finding the natural frequency and mode shapes of radial drilling machine structure.Finite element analysis has been done to find out the natural frequencies and mode shapes of radial drilling machine structure.Assembled mass and stiffness matrices are obtained for each element and solved by using inverse iteration technique.

scholarly journals Deformation Structures and Tool Wear during High-Speed Machining

2013 ◽  
Vol 10 (1) ◽  
pp. 12-17
Author(s):  
Karol Vasilko
Keyword(s):  
High Speed ◽  
Cutting Speed ◽  
Tool Material ◽  
Machining Process ◽  
Surface Dynamics ◽  
Machined Surface ◽  
Deformation Structures ◽  
Cutting Speeds ◽  
Tool Durability

Abstract Tendencies towards increasing cutting speeds during machining can be observed recently. The first wave of increasing cutting speeds occured in the 60s of the previous century. However, suitable tool material was not available at that time. Increasing cutting speed is possible only following the development of cutting material, resistant against high temperatures, abrasive, adhesive and diffusive wear. It is obvious that the process of chip creation, quality of machined surface, dynamics of machining process and temperature of cutting change considerably with cutting speed. To be able to apply higher cutting speeds in production machining, it is necessary to know the dependence of those characteristics on cutting speed. Some of those phenomena, which are linked with cutting speed, will be explained in the paper. Key words: machining, cutting speed, tool durability, surface quality

Modal Analysis of BT Spindle-Toolholder Interface Based on Abaqus/Standard

2013 ◽  
Vol 662 ◽  
pp. 632-636
Author(s):  
Yong Sheng Zhao ◽  
Jing Yang ◽  
Xiao Lei Song ◽  
Zi Jun Qi
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Modal Analysis ◽  
Dynamic Characteristics ◽  
High Speed ◽  
Element Model ◽  
Contact Theory ◽  
High Speed Machining ◽  
The Finite Element Model

The quality of high speed machining is directly related to dynamic characteristics of spindle-toolholder interface. The paper established normal and tangential interactions of BT spindle-toolholder interface based on finite element contact theory, and analysed free modal in Abaqus/Standard. Then the result was compared with the experimental modal analysis. It shows that the finite element model is effective and could be applied in the future dynamic study of high-speed spindle system.

scholarly journals Analysis of the Performance of Drilling Operations for Improving Productivity

2021 ◽  
Author(s):  
Majid Tolouei-Rad ◽  
Muhammad Aamir
Keyword(s):  
High Speed ◽  
Cutting Tools ◽  
High Speed Steel ◽  
Dimensional Accuracy ◽  
Vital Role ◽  
Machining Process ◽  
Drilling Process ◽  
Single Shot ◽  
Drilling Operations

Drilling is a vital machining process for many industries. Automotive and aerospace industries are among those industries which produce millions of holes where productivity, quality, and precision of drilled holes plays a vital role in their success. Therefore, a proper selection of machine tools and equipment, cutting tools and parameters is detrimental in achieving the required dimensional accuracy and surface roughness. This subsequently helps industries achieving success and improving the service life of their products. This chapter provides an introduction to the drilling process in manufacturing industries which helps improve the quality and productivity of drilling operations on metallic materials. It explains the advantages of using multi-spindle heads to improve the productivity and quality of drilled holes. An analysis of the holes produced by a multi-spindle head on aluminum alloys Al2024, Al6061, and Al5083 is presented in comparison to traditional single shot drilling. Also the effects of using uncoated carbide and high speed steel tools for producing high-quality holes in the formation of built-up edges and burrs are investigated and discussed.

Optimized Design and Performance Study of High Speed Five-Axis Machine Tools

2020 ◽  
Author(s):  
Tzu-Chi Chan ◽  
Jyun-Sian Yang
Keyword(s):  
Machine Tool ◽  
Dynamic Characteristics ◽  
Machine Tools ◽  
High Speed ◽  
Spectral Response ◽  
Work Piece ◽  
Static And Dynamic Characteristics ◽  
Five Axis ◽  
Speed Accuracy ◽  
Machine Structure

Abstract With the development of machine tools trending toward high precision, intelligence, multi-axis, and high speed, the improvement of the processing performance and rigidity of the machine is considerably important. The objective of this study is to design of a high-speed five-axis moving-column machine tool and perform structural analysis and optimization. We study the static and dynamic characteristics of the five-axis machine tool, design and improve the mechanical structure, and optimize the structural configuration of the machine. The entire machine structure is further analyzed and enhanced to improve its static and dynamic characteristics, including static rigidity, modal, transient, and spectral response characteristics. The static and dynamic characteristics of the machine structure directly affect the machine processing performance, and further affect the work piece precision machined by the tool. Through this study, the design technology for speed, accuracy, and surface roughness of the machine tool are further improved.

scholarly journals Selection of the optimal version of the rolling rings of stand no. 7 of mill 150 of OJSC “BSW Management Company of Holding “BMC” from various types of high-speed steel, providing the best indicator of operational durability

2020 ◽  
pp. 43-47
Author(s):  
I. A. Guzova ◽  
I. A. Kovaleva ◽  
P. A. Babkov
Keyword(s):  
Chemical Composition ◽  
High Speed ◽  
High Speed Steel ◽  
Significant Development ◽  
Management Company ◽  
Long Period ◽  
Operational Characteristics ◽  
Rolling Ring ◽  
Selection Of

Rolling rings as an important element of the rolling mill belong to the category of replaceable equipment, the quality of performance of which affects a number of operational characteristics, as well as the quality of rolled products. The material from which the rolling ring of the stand No. 7 is made must have the appropriate properties capable of perceiving high thermal loads for a long period of time without destruction, chipping and significant development of calibers. In this regard, there is a need to select the optimal option for the manufacture of rolling rings that can withstand such loads for a sufficiently long period of time. The study of the causes of destruction of the rolling ring 450×242×100 mm of high-speed steel, used at OJSC «BSW – Management Company of the Holding «BMC» in the cage number 7 mill 150 rolling shop. The results of metallographic studies of the microstructure and chemical composition of fragments of the destroyed rolling ring are presented. A detailed study and comparative analysis of the chemical composition and microstructure of samples of similar rings made of high-speed steel from two different suppliers, which showed high results in durability during operation, was carried out.

Influence of Cutting Conditions on Surface and Sub-Surface Quality of High Speed Dry End Milling Ti-6Al-4V

2014 ◽  
Vol 67 (3) ◽  
Author(s):  
H. Safari ◽  
S. Izman
Keyword(s):  
Plastic Deformation ◽  
Tool Wear ◽  
Surface Quality ◽  
High Speed ◽  
End Milling ◽  
Cutting Parameters ◽  
Machining Process ◽  
Surface Alteration ◽  
Cutting Speeds

Surface quality is one of the most critical restraints for determining cutting parameters and selecting of machining process in metal cutting process. In this study, the effects of cutting parameters and tool wear on the surface and sub-surface quality of high speed dry end milling Ti-6Al-4V were investigated. PVD Coated carbide tools were used under different high cutting speeds and feed rates. The quality of the machined surface and corresponding alteration on the sub-surface and entry/exit edges were characterized through scanning electron microscopy. The results showed that the better surface quality was obtained when machining at higher cutting speeds and feed rates. High speed dry end milling using the worn tool causes to plastic deformation of the alloy which is resulted in developing the lamellae on the surface and causing poor surface finish. Worn tools with the uniform tool wear land generated better surface quality compare to those with chipping and flaking on the tool edge surface. Tool wear is suggested as the other contributing factor in developing entry and exit edge damages. The results of sub-surface alteration measurement revealed that the worn tool enhanced the sub-surface alteration resulted in 45% increase in plastic deformation compare to the new tool.

An Optimization Model of High-Speed and High-Precision Machining Based on Model Predictive Control

2018 ◽  
Author(s):  
Jing Zhang ◽  
Jiexiong Ding ◽  
Qingzhao Li ◽  
Qicheng Ding ◽  
Zhong Jiang ◽  
...  
Keyword(s):  
Model Predictive Control ◽  
High Precision ◽  
Predictive Control ◽  
Feed Rate ◽  
Optimization Model ◽  
High Speed ◽  
Machining Process ◽  
Precision Machining ◽  
Contouring Error

In the multi-axis high-speed and high-precision machining process, the contouring error and the feed rate of tool tip and affect the quality of machined workpiece and the processing efficiency, respectively. The faster feed motion will result in greater tracking error of each axis. The contouring error which directly affects the quality of machined part is caused by the tracking errors of the axes. Obviously, it is difficult to improve the contouring accuracy and increase the feed rate simultaneously. To this end, a novel optimization model is developed here based on the model predictive control method. First, the feed servo model of translational and rotary axes are established, and the contouring error model is afterwards constructed. Subsequently, the optimization algorithm is derived to achieve the high processing speed, and input constraints are addressed to avoid violation of the performance limitation of the drivers. In addition, contouring error constraint, which is obtained by calculating the contouring error of the processed path, is addressed to high contour accuracy. Finally, a simulation is conducted to verify the effectiveness and superiority of the proposed method.

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