scholarly journals OPTIMIZATION OF SOME WEAVING MACHINE PARTS DESIGN. THEORETICAL APPROACH

2021 ◽  
Vol 2021 ◽  
pp. 215-221
Author(s):  
A. Mostafa ◽  
W. Hashima ◽  
S. El-Gholmy ◽  
A. Al-Oufy ◽  
M. Hassan
Keyword(s):  
High Speed ◽  
Natural Frequencies ◽  
Operating Time ◽  
Research Work ◽  
Element Model ◽  
Vibration Modes ◽  
Work Study ◽  
Mechanical Factors ◽  
Machine Parts ◽  
The Cost

The factors of increasing productivity, reducing the cost and the quality improvement are the most important research concerns in weaving machinery. Increasing the effectiveness and productivity of production were achieved by increasing the operating time and efficiency of weaving looms. Thus, the manufacturers of weaving equipment attempt to minimize factors that limit production speed and production conditions. Heald frame is one of the known parts of the weaving machine that causes vibrations and noise which are important factors that influence high-speed development of looms. In this research work, study of mechanical factors (stresses and vibration) has been investigated for heald shaft. Finite element model of the heald frame was constructed to simulate different type of material. Then some important natural frequencies and vibration modes are calculated and the results. Results show a major improvement with the usage of these different material. As well as the failure of heald shaft is mainly due to friction and vibration and not due to the stresses or weight.

scholarly journals Vibration of Rotating and Revolving Planet Rings with Discrete and Partially Distributed Stiffnesses

2020 ◽  
Vol 11 (1) ◽  
pp. 127
Author(s):  
Fuchun Yang ◽  
Dianrui Wang
Keyword(s):  
High Speed ◽  
Differential Operators ◽  
Natural Frequencies ◽  
Rotation Speed ◽  
Distribution Area ◽  
Vibration Modes ◽  
Governing Equations ◽  
Vibration Properties ◽  
Wide Range ◽  
Forced Responses

Vibration properties of high-speed rotating and revolving planet rings with discrete and partially distributed stiffnesses were studied. The governing equations were obtained by Hamilton’s principle based on a rotating frame on the ring. The governing equations were cast in matrix differential operators and discretized, using Galerkin’s method. The eigenvalue problem was dealt with state space matrix, and the natural frequencies and vibration modes were computed in a wide range of rotation speed. The properties of natural frequencies and vibration modes with rotation speed were studied for free planet rings and planet rings with discrete and partially distributed stiffnesses. The influences of several parameters on the vibration properties of planet rings were also investigated. Finally, the forced responses of planet rings resulted from the excitation of rotating and revolving movement were studied. The results show that the revolving movement not only affects the free vibration of planet rings but results in excitation to the rings. Partially distributed stiffness changes the vibration modes heavily compared to the free planet ring. Each vibration mode comprises several nodal diameter components instead of a single component for a free planet ring. The distribution area and the number of partially distributed stiffnesses mainly affect the high-order frequencies. The forced responses caused by revolving movement are nonlinear and vary with a quasi-period of rotating speed, and the responses in the regions supported by partially distributed stiffnesses are suppressed.

Dynamic Characteristics of a Long-Span Cable-Stayed Bridge

2011 ◽  
Vol 480-481 ◽  
pp. 1496-1501
Author(s):  
Liu Hui
Keyword(s):  
Finite Element ◽  
Dynamic Characteristics ◽  
Iteration Method ◽  
Natural Frequencies ◽  
Element Model ◽  
Vibration Modes ◽  
Cable Stayed Bridge ◽  
Long Span ◽  
Subspace Iteration ◽  
Floating System

In order to study the dynamic characteristics of a super-long-span cable-stayed bridge which is semi-floating system, the spatial finite element model of this cable-stayed bridge was established in ANSYS based on the finite element theory.Modal solution was conducted using subspace iteration method, and natural frequencies and vibration modes were obtained.The dynamic characteristics of this super-long-span cable-stayed bridge were then analyzed.Results showed that the super-long-span cable-stayed bridge of semi-floating system has long basic cycle, low natural frequencies, dense modes and intercoupling vibration modes.

Vibration Response of a Thin-Walled Cylindrical Pipe with Liquid

2012 ◽  
Vol 189 ◽  
pp. 345-349
Author(s):  
Yu Lan Wei ◽  
Bing Li ◽  
Li Gao ◽  
Ying Jun Dai
Keyword(s):  
Finite Element ◽  
Natural Frequencies ◽  
Element Model ◽  
Beam Model ◽  
Vibration Modes ◽  
Timoshenko Beam Model ◽  
Cylindrical Pipe ◽  
Bending Vibration ◽  
Beam Bending ◽  
Thin Walled

Vibration characteristics of the thin-walled cylindrical pipe are affected by the liquid within the pipe. The natural frequencies and vibration modes of the pipe without liquid are analyzed by the theory of beam bending vibration and finite element model, which is based on the Timoshenko beam model. The first three natural frequencies and vibration modes of the pipe with or without liquid are acquired by experiments. As shown in the experiment results, the natural frequencies of the containing liquid pipe are lower than the natural frequencies of the pipe without liquid.

Dynamics Behaviors Analysis on the Column of Gear Grinding Machine

2012 ◽  
Vol 472-475 ◽  
pp. 1885-1888
Author(s):  
Ya Hui Wang ◽  
Xiao Zhong Ren
Keyword(s):  
Theoretical Basis ◽  
Natural Frequencies ◽  
Element Model ◽  
Vibration Modes ◽  
Ansys Software ◽  
Dynamic Behaviors ◽  
Structural Improvement ◽  
Gear Grinding ◽  
Column Structure ◽  
Grinding Machine

Aiming at the issue on the development of gear form grinding machine, a method for analyzing the dynamic behaviors of the machine column was introduced. Based on the model of gear grinding machine developed before, a suitable finite element model of the column was established firstly. Modal analysis on the column was carried out by means of ANSYS software, and the first five natural frequencies and vibration modes of the column were obtained. According to the analysis results, some improvements on the original column structure were made. By comparing the static and dynamic behaviors of several different rib structures presented, the best column structure is selected. This method offers theoretical basis for the structural improvement of gear grinding machine.

scholarly journals DEVELOPMENT OF A DESIGN METHOD FOR DETERMINING THE ATTACHMENT OF THE EXHAUST MOUNTING MOUNTS

Akustika ◽  
2019 ◽  
Vol 34 ◽  
pp. 141-147
Author(s):  
Rakhmatjon Rakhmatov ◽  
Vitaliy Krutolapov ◽  
Valeriy Zuzov
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Strain Energy ◽  
Natural Frequencies ◽  
Design Method ◽  
Exhaust System ◽  
Element Model ◽  
Vehicle Body ◽  
Vibration Modes ◽  
The Finite Element Model

The article presents the developed method of determining the attachment points of the mounts of the exhaust system to the vehicle body. The requirements for the construction of a finite element model of the exhaust system are presented, the finite element model of the exhaust system is created, the results of natural frequencies and vibration modes and the strain energy of the structure are shown.

Simulation Study on the Control Valve in Hydraulic Operating Mechanism of the High Voltage Circuit Breaker

2008 ◽  
Author(s):  
Wei Liu ◽  
Huayong Yang ◽  
Bing Xu ◽  
Zhongyu Wu
Keyword(s):  
High Voltage ◽  
High Speed ◽  
Circuit Breaker ◽  
Operating Time ◽  
Research Work ◽  
Control Valve ◽  
Simulation Software ◽  
Operating Mechanism ◽  
High Voltage Circuit Breaker ◽  
The Operating Mechanism

High voltage circuit breaker is an important interrupting device in a power system network. The operating mechanism is a key component of circuit breakers. The action of hydraulic operating mechanism in circuit breaker is different from general hydraulic mechanism for its high speed, short operating time and high pressure. In this paper, the working principle of hydraulic operating mechanism of 252kv high voltage circuit breaker is introduced. The high response speed solenoid pilot direction control valve is analyzed. The dynamic characteristic of the valve affects the performance of the hydraulic operating mechanism. Mathematical models of the valve and system have been developed. Simulations are carried out with AMESIM, hydraulic simulation software, and ANSOFT, electromagnetic simulation software. The characteristics of the operating mechanism control valve are discussed with the consideration of the influence of the geometry and environmental parameters. As the result of the research work, the simulation models and results provide the effectively theoretical guidance for the design and optimization of hydraulic operating mechanism.

Mechanical Shock FE Modeling for ATCA Circuit Board Design

2005 ◽  
Author(s):  
Frank Z. Liang ◽  
Larry M. Palanuk ◽  
Wade Hezeltine
Keyword(s):  
High Speed ◽  
Natural Frequencies ◽  
Mechanical Design ◽  
Element Model ◽  
Circuit Board ◽  
Mechanical Shock ◽  
Risk Areas ◽  
Processor Unit ◽  
Communication Equipment ◽  
Modal Method

ATCA is a new form factor for communication equipment applications. Finite element model (FEM) was created to predict the dynamic response of an ATCA design during a table drop shock. The model was built with 2nd order brick elements for minimizing the meshing sensitivity. Modal method was used and followed by dynamic transient analysis with superposition approach and validated by comparing the modal test data for matching the natural frequencies and the modal shapes. The model was further validated by comparing the board displacement with direct displacement measurement using a high speed camera. As a result the localized board strain predictions matched the measured board strain at each networking processor unit. The validated model was used to predict the risk areas for solder joints, which later proved to be accurate during board design verification tests. This paper presents the modeling and model validation processes, as well as the ATCA mechanical design evaluations.

Modal Analysis of the Frame of YlJ Series Tire Uniformity Testing Machine

2013 ◽  
Vol 561 ◽  
pp. 201-205
Author(s):  
Zhen Ya Duan ◽  
Bo Song ◽  
Guan Ying Song ◽  
Zhong Yu Lu ◽  
Bai Lin Hang
Keyword(s):  
Natural Frequencies ◽  
Testing Machine ◽  
Great Influence ◽  
Element Model ◽  
Test Accuracy ◽  
Structure Parameters ◽  
Vibration Modes ◽  
Theoretical Support ◽  
Force Variation ◽  
Working Frequency

A finite element model of the frame was established based on studying structure parameters of the YLJ series tire uniformity testing machine (TUTM). For the purpose of dynamic analysis of the frame of the YLJ series TUTM, make use of model analysis function of ANSYS to work out the first six-mode natural frequencies and vibration modes. Analysis results show that the first three-mode frequencies of the frame are 20.7 Hz, 21.9 Hz and 30.8Hz, which are far greater than working frequency of the spindle, 1 Hz. As is known, the natural frequency of the frame should be forty times more than the rotation of tire when the force variation of the tire is decomposed into tenth harmonic. In this situation, the low mode natural frequencies of the frame cannot meet this requirement, which have great influence on the test accuracy of the TUTM. The research results in this paper will provide helpful theoretical support to improve test accuracy of the YLJ series TUTM．

Fault Diagnosis of Wind Turbine Gearboxes

2012 ◽  
Vol 512-515 ◽  
pp. 715-718
Author(s):  
Yu Bai Zhang ◽  
Hui Qun Yuan ◽  
Yin Xin Yu ◽  
Hai Jiang Kou ◽  
Ming Xuan Liang
Keyword(s):  
Wind Turbine ◽  
High Speed ◽  
Fault Location ◽  
Natural Frequencies ◽  
Experimental Tests ◽  
Element Model ◽  
Frequency Domain Analysis ◽  
Mode Shapes ◽  
Frequency Components ◽  
The Finite Element Model

Abnormal vibration appeared when experimental tests was carried out on gearboxes of a 1.5MW wind turbine. In this paper, Time-domain and frequency- domain analysis of test data was implemented based on the method of wavelet denoising, the fault location was determined, and the vibration fault indicators and frequency components were obtained. The finite element model of the gearboxes were established, and the natural frequencies and mode shapes were achieved by calculating. The results showed that the fault occurred in the high speed shaft parts, fault vibration frequency was caused by high-speed shaft eccentric resonance frequency and the frequency generated by the natural frequency and the edge frequency that caused by turning. The research layed the foundation for the study of noise reduction and optimization of the wind turbine gearboxes.

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