Dynamic Characteristics of an Active Vibrocontact Monitoring System for Multipurpose Machine Tools

Linear rolling guide has gained wide application in various CNC machines. As a main joint of the machine tools, it makes great impact on the dynamic characteristics of machine tools. It is therefore necessary to study the dynamic behavior of linear rolling guide. And external load is a factor that affects the dynamic characteristics of linear rolling guide. In this paper experimental approach was used with the aim of studying effects of external load on dynamic behavior of linear rolling guide. The experiment contained some modal tests of linear rolling guide ways when they were loaded forces of different sizes.

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Design Optimization of Machine-Tool Structures With Respect to Dynamic Characteristics

Journal of Mechanisms Transmissions and Automation in Design ◽

10.1115/1.3267353 ◽

1983 ◽

Vol 105 (1) ◽

pp. 88-96 ◽

Cited By ~ 15

Author(s):

M. Yoshimura ◽

T. Hamada ◽

K. Yura ◽

K. Hitomi

Keyword(s):

Machine Tool ◽

Design Optimization ◽

Dynamic Characteristics ◽

Machine Tools ◽

Structural Model ◽

Optimization Method ◽

Practical Applications ◽

Design Variables ◽

Design Changes ◽

Machine Tool Structures

This paper proposes a design optimization method in which simplified structural models and standard mathematical programming methods are employed in order to optimize the dynamic characteristics of machine-tool structures in practical applications. This method is composed of three phases: (1) simplification, (2) optimization, and (3) realization. As design variables employed in this optimization are greatly reduced, machine-tool structures are optimized effectively in practice. With large design changes being conducted through this multiphase procedure, dynamic characteristics of machine tools can be greatly improved. This method is demonstrated on a structural model of a vertical lathe.

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Numerical Investigation of Static and Dynamic Characteristics of Water Hydrostatic Porous Thrust Bearings

International Journal of Automation Technology ◽

10.20965/ijat.2011.p0773 ◽

2011 ◽

Vol 5 (6) ◽

pp. 773-779 ◽

Cited By ~ 6

Author(s):

Yuki Nishitani ◽

◽

Shigeka Yoshimoto ◽

Kei Somaya

Keyword(s):

Porous Material ◽

Dynamic Characteristics ◽

Machine Tools ◽

Measuring Equipment ◽

Load Capacity ◽

Damping Coefficient ◽

Static And Dynamic Characteristics ◽

Thrust Bearings ◽

Hydrostatic Bearings ◽

Aerostatic Bearings

A moving table supported by aerostatic bearings can achieve excellent accuracy of motion because of its noncontact support and, hence, it is used in various precision machine tools and measuring equipment. However, because of low viscosity of air, the damping coefficient of aerostatic bearings is not very high, causing vibration with nanometer-order amplitudes. The accuracy of machine tools and measuring equipment could deteriorate because of this vibration. It is expected that water hydrostatic bearings would have a higher damping coefficient than aerostatic bearings due to the higher viscosity of water. In addition, water, like air, does not pollute the environment. In this paper, the static and dynamic characteristics of water hydrostatic thrust bearings using porous material were numerically investigated and comparedwith conventional pocket hydrostatic bearings with a capillary restrictor. Hydrostatic porous bearings can be easily constructed because the porous material becomes a viscous restrictor itself. It was consequently found that water hydrostatic porous thrust bearings have higher maximum load capacity and slightly lower stiffness than water bearings with a capillary restrictor.

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Analysis on Dynamic Characteristics of Closed Hydrostatic Guideway Throttled by Capillary

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.607.594 ◽

2014 ◽

Vol 607 ◽

pp. 594-599

Author(s):

Xiao Chuang Zhu ◽

Wei Guo Gao ◽

Teng Liu ◽

Sheng Hui Zhao ◽

Guan Wei Zhang ◽

...

Keyword(s):

Dynamic Characteristics ◽

Machine Tools ◽

High Capacity ◽

Volume Effect ◽

Damping Coefficient ◽

Theoretical Research ◽

Oil Film ◽

Damping Effect ◽

Ultra Precision ◽

Precision Machine Tools

Hydrostatic guideway is widely used in heavy and ultra-precision machine tools due to their high bearing capacity, low coefficient of friction and high capacity of precision-remaining. So it is necessary to carry on theoretical research on its dynamic characteristics. Firstly, the oil-film damping coefficient of closed hydrostatic guideway throttled by capillary is derived. Secondly, a new dynamic mathematical model, considering the oil damping effect, the extrusion effect and the volume effect, of the closed hydrostatic guideway is proposed. Thirdly, the frequency characteristics and step characteristics of it are simulated in Matlab Simulink through the transfer function. Finally, the paper investigates the influence of damping coefficient, the oil pressure, volume effect and the initial oil-film thickness on the dynamic characteristics of closed hydrostatic guideway throttled by capillary.

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Application of Piezoelectricity Acceleration Sensor to Dynamic Characteristics Monitoring of Tied Arch Bridge

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.184-185.715 ◽

2012 ◽

Vol 184-185 ◽

pp. 715-718 ◽

Cited By ~ 1

Author(s):

Yi Li ◽

Zhong Guo ◽

Hua Wei

Keyword(s):

Real Time ◽

Monitoring System ◽

Dynamic Characteristics ◽

Health Monitoring ◽

Damping Ratio ◽

Vibration Signal ◽

Mode Shapes ◽

Acceleration Sensor ◽

Arch Bridge ◽

Tied Arch Bridge

In bridge structural health monitoring, random vibration test and monitoring bridge dynamic characteristics provides an effective method for evaluation of bridge safety and serviceability performance. Piezoelectric accelerometer overcome the draw backs of the traditional sensor characteristic measuring instrument which are functional singleness and monopoly used, a piezoelectricity acceleration sensor performance analysis and dynamic characteristics monitoring system base on a tied arch bridge health monitoring system was designed, and the hardware structure and software of the system were introduced, acquired vibration signal can be displayed, stored, analyzed and processed in real time. The vibration frequency of the bridge structure, mode shapes and damping ratio is calculated base on the monitoring data, and the amplitude of frequency domain shows that the system was validated in actual real-time monitoring of bridge dynamic characteristics.

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