Analysis of Particle Damping Characteristics on Steel Vertical Machining Centre Column with Epoxy Reinforced Granite

2020 ◽  
Vol 50 ◽  
pp. 94-102
Author(s):  
S. Nallusamy ◽  
K. Sujatha ◽  
K. Rajan ◽  
K.R. Vijaya Kumar
Keyword(s):  
Cast Iron ◽  
Machine Tool ◽  
High Speed ◽  
Good Choice ◽  
Work Piece ◽  
Damping Capacity ◽  
Static Stiffness ◽  
Machining Performance ◽  
Machine Tool Structure ◽  
Steel Balls

In high speed machining, performance is generally influenced by the dynamic behaviour of the machine tool structures. The machine tool structure is required to be rigid in order to remove the undesirable vibration and to improve the work piece quality. The most conventional material used in machine tool structure is cast iron which has both stiffness and dynamic characteristics to perform at varying speeds. The objective of this work is to improve damping capacity of vertical machining centre column. The damping capacity of column can be increased further by using passive damping method of ball packing. Damping capacity is a crucial factor which makes the dissipation of vibration happens at faster rate. As compared with cast iron established studies shows that epoxy granite a composite material improves damping capacity. Epoxy granite though could be a good choice for improving the machine tool performance at high speeds but is poor in static stiffness compared to cast iron. In this investigation it was observed that, the static stiffness of epoxy granite composite vertical machining centre column could be increased by using steel reinforcements. The final results reveal that, steel balls with epoxy granite provide faster dissipation time of 15ms at 70% packing ratio as compared to glass balls that showed dissipation time of 35ms. Also it was seen that, the steel balls offer the better damping capacity at optimum packing ratio of 50% mainly due to its specific gravity and mass of the balls.

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.

Structural investigation of steel-reinforced epoxy granite machine tool column by finite element analysis

2019 ◽  
Vol 233 (11) ◽  
pp. 2267-2279 ◽  
Author(s):  
Prabhu Raja Venugopal ◽  
M Kalayarasan ◽  
PR Thyla ◽  
PV Mohanram ◽  
Mahendrakumar Nataraj ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Cast Iron ◽  
Machine Tool ◽  
Dynamic Characteristics ◽  
Element Model ◽  
Static Stiffness ◽  
Element Analysis ◽  
Static And Dynamic Characteristics ◽  
Machining Center

Higher damping with higher static stiffness is essential for improving the static and dynamic characteristics of machine tool structures. The structural vibration in conventional machine tools, which are generally made up of cast iron and cast steel, may lead to poor surface finish and the dimensional inaccuracy in the machined products. It leads to the investigation of alternative machine tool structural materials such as concrete, polymer concrete, and epoxy granite. Although epoxy granite has a better damping capacity, its structural stiffness (Young's modulus) is one-third as compared to cast iron. Therefore, the present work represents optimization of the structural design of the vertical machining center column by introducing various designs of steel reinforcement in the epoxy granite structure to improve its static and dynamic characteristics using experimental and numerical approaches. A finite element model of the existing cast iron vertical machining center column has been developed and validated against the experimental data obtained using modal analysis. Furthermore, finite element models for various epoxy granite column designs have been developed and compared with the static and dynamic characteristics of cast iron column. A total of nine design configurations for epoxy granite column with steel reinforcement are evolved and numerical investigations are carried out by finite element analysis. The proposed final configuration with standard steel sections has been modeled using finite element analysis for an equivalent static stiffness and natural frequencies of about 12–20% higher than cast iron structure. Therefore, the proposed finite element model of epoxy-granite-made vertical machining center column can be used as a viable alternative for the existing column in order to achieve higher structural damping, equivalent or higher static stiffness and, easy and environmental-friendly manufacturing process.

scholarly journals Investigation of the negative influence of cooling lubricants on the deformation of the machine tool structure

2019 ◽  
Vol 95 ◽  
pp. 04006
Author(s):  
Christian Brecher ◽  
Filippos Tzanetos ◽  
Daniel Zontar
Keyword(s):  
Machine Tool ◽  
Thermal State ◽  
Negative Impact ◽  
Negative Influence ◽  
Work Piece ◽  
Ongoing Research ◽  
Thermally Induced ◽  
Machine Tool Structure ◽  
Tool Centre Point ◽  
The Impact

Cooling lubricants have a significant influence on the thermal state of a machine tool. The fluid absorbs the thermal energy of the cutting process and dissipates it to prevent wear of the tool and distortion of the work piece. However, the unpredictable flow of the cooling lubricant also transfers the energy to the machine tool structure and can thus have a negative impact on the produced work piece quality. While the thermal behaviour of machine tools under the influence of thermal environmental conditions is already the subject of ongoing research projects, the influence of cooling lubricants on the thermal state of the machine tool and thus the achievable manufacturing accuracy is still largely unexplored. This paper investigates the thermally induced deformations of the machine tool structure, as well as the impact on the Tool Centre Point (TCP).

An Analysis and Modeling of the Dynamic Stability of the Cutting Process Against Self-Excited Vibration

2020 ◽  
Vol 22 (4) ◽  
pp. 1287-1300
Author(s):  
A. Motallebia ◽  
A. Doniavi ◽  
Y. Sahebi
Keyword(s):  
Machine Tool ◽  
Removal Rate ◽  
Dimensional Accuracy ◽  
Modal Testing ◽  
Cutting Process ◽  
Work Piece ◽  
Stability Diagrams ◽  
Machine Tool Structure ◽  
Excited Vibration ◽  
The Stability

AbstractChatter is a self-excited vibration which depends on several parameters such as the dynamic characteristics of the machine tool structure, the material of the work piece, the material removal rate, and the geometry of tools. Chatter has an undesirable effect on dimensional accuracy, smoothness of the work piece surface, and the lifetime of tools and the machine tool. Thus, it is useful to understand this phenomenon in order to improve the economic aspect of machining. In the present article, first the theoretical study and mathematical modeling of chatter in the cutting process were carried out, and then by performing modal testing on a milling machine and drawing chatter stability diagrams, we determined the stability regions of the machine tool operation and recognized that witch parameter has a most important effect on chatter.

Hybrid modeling and analysis of multidirectional variable stiffness of the linear rolling guideway under combined loads

2020 ◽  
Vol 234 (13) ◽  
pp. 2716-2727
Author(s):  
Lei Yang ◽  
Lei Wang ◽  
Wanhua Zhao
Keyword(s):  
Machine Tool ◽  
High Speed ◽  
Complex Loading ◽  
Variable Stiffness ◽  
Time Varying ◽  
Modeling And Analysis ◽  
Combined Loads ◽  
Machine Tool Structure ◽  
High Feed ◽  
Stiffness Characteristics

In the working process of high-speed multiaxis machine tools, inertial loads due to high feed acceleration and time-varying gravity loads due to changing configuration of multiaxis structure result in time-varying complex loads applied to linear rolling guideway. Existing models cannot efficiently represent the effect of complex loads on multidirectional stiffness variation of linear rolling guideway. In this paper, a hybrid model of multidirectional stiffness of linear rolling guideway and the solving algorithm are proposed. The complex loading conditions of linear rolling guideway in high-speed multiaxis machine tool structure are considered. And contact flexibilities between rolling balls and grooves are modeled with the effect of elastic deformations of runner block and rail. The proposed model can calculate the multidirectional stiffness with high accuracy. Meanwhile the differences between the stiffness characteristics in different directions are represented correctly. The variations of multidirectional stiffness of linear rolling guideway under time-varying combined loads are analyzed. This study provides an effective way to comprehensively evaluate the stiffness characteristics of linear rolling guideway which can contribute to the dynamic analysis and active design of high-speed machine tool structure.

scholarly journals New High-Speed Machine Tool Structure by Holistic Mechatronic Systems Design

Procedia CIRP ◽  
2012 ◽  
Vol 1 ◽  
pp. 307-312 ◽  
Author(s):  
R. Neugebauer ◽  
S. Ihlenfeldt ◽  
U. Frieß ◽  
M. Wabner ◽  
S. Rauh
Keyword(s):  
Machine Tool ◽  
High Speed ◽  
Systems Design ◽  
Mechatronic Systems ◽  
Machine Tool Structure ◽  
High Speed Machine

Application of Sandwich-Based Designs on Main Structural Parts of Machine Tools

2011 ◽  
Author(s):  
Jan Smoli´k ◽  
Viktor Kuli´sˇek ◽  
Miroslav Janota
Keyword(s):  
Machine Tool ◽  
Machine Tools ◽  
High Speed ◽  
High Performance ◽  
Transportation Industry ◽  
Static Stiffness ◽  
Modal Damping ◽  
Machine Tool Structures ◽  
Structural Parts

New, higher and challenging properties of new high-speed machines and high-performance machines bring up many questions connected to the design and properties of the main machine tool structures. Parameters like static stiffness, eigenfrequencies, modal damping and mass of parts may be identified as very important, and all these properties need to be improved. The most important material properties in the field of machine tools are presented in this paper. A case study based on a modification of a real horizontal machining centre is introduced. The modification consists in using a sandwich design concept in the main structural machine tool part. The sandwich concept, widely known and used in the aerospace industry and, more generally, the transportation industry, is not commonly used in machine tool design. A significant reduction of mass has been achieved by manufacturing a hybrid column with aluminum foam cores, while static stiffness has not been affected.

scholarly journals An Analysis and Modeling of the Dynamic Stability of the Cutting Process Against Self-Excited Vibration

2019 ◽  
Vol 23 (1) ◽  
pp. 28-35
Author(s):  
A. Motallebia ◽  
A. Doniavi ◽  
Y. Sahebi
Keyword(s):  
Machine Tool ◽  
Removal Rate ◽  
Dimensional Accuracy ◽  
Modal Testing ◽  
Cutting Process ◽  
Work Piece ◽  
Stability Diagrams ◽  
Machine Tool Structure ◽  
Excited Vibration ◽  
The Stability

Abstract Chatter is a self-excited vibration that depends on several parameters such as the dynamic characteristics of a machine tool structure, the material of work piece, the material removal rate, and the geometry of tools. Chatter has an undesirable effect on dimensional accuracy, smoothness of work piece surface, lifetime of tools and machine tools. Thus, it is useful to understand this phenomenon in order to improve the economic aspect of machining. In the present article, firstly, the theoretical study and mathematical modeling of chatter in the cutting process were carried out. Then, by performing modal testing on a milling machine and drawing chatter stability diagrams, we determined the stability regions of the machine tool operation and recognized the parameter that had the most important effect on chatter.

High-speed test of thermal effects for a machine-tool structure based on modal analysis

1986 ◽  
Vol 8 (2) ◽  
pp. 72-78 ◽  
Author(s):  
M. Matsuo ◽  
T. Yasui ◽  
T. Inamura ◽  
M. Matsumura
Keyword(s):  
Machine Tool ◽  
Modal Analysis ◽  
Thermal Effects ◽  
High Speed ◽  
Speed Test ◽  
Machine Tool Structure

Stress and Vibration Analysis of a Lathe Bed Made of Aluminum-Copper Alloy for High Speed Machining

2009 ◽  
Vol 15 ◽  
pp. 81-88 ◽  
Author(s):  
R. Torres-Martínez ◽  
G. Urriolagoitia-Calderón ◽  
G. Urriolagoitia-Sosa ◽  
R. Espinoza-Bustos
Keyword(s):  
Cast Iron ◽  
High Speed ◽  
Natural Frequencies ◽  
Mechanical Design ◽  
Parametric Modeling ◽  
High Speed Machining ◽  
The Finite Element Method ◽  
Cu Alloy ◽  
Design Variables ◽  
Machine Tool Structure

The analysis of the rigidity of an Al-Cu alloy lathe bed to be used for high speed machining (HSM) is presented in this work. Mechanical design optimization by means of simulations based on the finite element method (FEM) was applied in order to calculate the lathe bed deflections, the natural frequencies and the corresponding vibration amplitudes. For the parametric modeling, a prototype lathe to be used in conventional speed machining (CSM) with a cast iron bed was considered. The optimized parameter was the stress in the lathe bed, considering as a restriction the allowable deflection in a node of the machine-tool structure. The design variables were the height, the thickness, and the length of the wall of the lathe bed. The lathe bed was loaded with cutting and inertial forces due to HSM in order to demonstrate that the evaluated stresses and vibration amplitudes are in an acceptable level according to ISO Standards (system of limits and fits in workpieces). The results show the feasibility of using an Al-Cu alloy instead of cast iron in the fabrication of lathe beds. This increases the flexibility of manufacture.

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