scholarly journals Change in the Natural Vibration Frequency Spectrum of the Steel Pipe Mathematic Model Depending on Sizes, Location, and Number of Local Defects

2015 ◽  
Vol 4 (2) ◽  
pp. 3-15
Author(s):  
Суслонов ◽  
A. Suslonov ◽  
Самарин ◽  
V. Samarin ◽  
Сущев ◽  
...  
Keyword(s):  
Natural Vibration ◽  
Mathematic Model ◽  
Steel Pipe ◽  
Nonlinear Dependence ◽  
Natural Vibration Frequency ◽  
Local Defect ◽  
Vibration Frequencies ◽  
Element Analysis ◽  
Pipe Model ◽  
Local Defects

The article discusses issues related to the research of the influence of sizes and location of local defects on the change in the natural vibration frequencies spectrum of the steel pipe model fixed on a single threshold. The research was made using the finite element analysis (FEA) and the SCAD computing system. Nonlinear dependence of the natural vibration frequencies on the defect size and its location was ascertained. Such nonlinearity in the course of defects accumulation is classified as a genetic nonlinearity. Completed research reveals that the scale and the location of defects can be determined by the pattern of their change during the monitoring of main dynamic characteristics in the course of the building operation. It has been ascertained that the first frequency of torsional natural vibrations of the pipe declines with greater intensity than the first and other lateral vibration frequencies in case of a specific location of a growing local defect. There have been no regulatory requirements for the time being to the analysis of structures (flue stacks) subject to torsional vibrations. However, for example, it was ascertained during the expert examination of anchoring of a steel pipe in service and having vertical stiffeners throughout the height that all the anchors damaged circumferentially have an inclination to one and the same side. Furthermore, the value of such an inclination coincides with results of observations of the pipe top deviation change in azimuth. An attempt was made during the research to determine the limit value of frequencies that would correspond to occurrence of the first, the second or the third limit states of operated construction structures with defects.

Dynamic Response Characteristic Analysis of the Wind Turbine Tubular Tower Based on ANSYS Workbench

2010 ◽  
Vol 33 ◽  
pp. 580-582 ◽  
Author(s):  
Zhao Hui Liu ◽  
Xiao Jun Wang
Keyword(s):  
Dynamic Response ◽  
Wind Turbine ◽  
Natural Vibration ◽  
Response Characteristic ◽  
Design Parameters ◽  
Vibration Frequencies ◽  
Characteristic Analysis ◽  
Element Analysis ◽  
Dynamic Response Characteristic ◽  
Ansys Workbench

Finite element analysis and the ANSYS Workbench software is used to analyze the dynamic response characteristic of wind turbine tubular tower and solve out the natural vibration frequencies. That result is used to verify the design parameters and optimize the tubular tower.

Finite Element Analysis of Natural Vibration Frequency for Unbounded Prestressed Concrete Beams

2013 ◽  
Vol 351-352 ◽  
pp. 1034-1037
Author(s):  
Feng Ge Li ◽  
Yan Zhao
Keyword(s):  
Finite Element ◽  
Vibration Frequency ◽  
Prestressed Concrete ◽  
Natural Vibration ◽  
Concrete Beams ◽  
Variable Stiffness ◽  
Natural Vibration Frequency ◽  
Element Analysis ◽  
Finite Element Program ◽  
Element Program

An experimental investigation on the dynamic characteristics of unbounded prestressed concrete simply support beams is presented. A total of 5 unbounded prestressed concrete simply support beams were constructed and tested. The influence of prestressing on natural vibration frequency of concrete beams is studied by applying prestress gradually. A model of variable stiffness is proposed to calculate the natural vibration frequency of unbounded prestressed concrete beams. The finite element program Sap2000 is used to calculate the frequency of unbounded prestressed concrete beams. The results show that the calculating results agree well with experimental ones.

Application of mathematical modeling methods to determine the effect of soil on natural vibration frequencies of pipelines

2021 ◽  
Vol 14 (2) ◽  
pp. 142-147
Author(s):  
V. E. Chanchina ◽  
S. O. Gaponenko ◽  
A. E. Kondratyev ◽  
A. O. Fedotova ◽  
G. R. Mustafina
Keyword(s):  
Modal Analysis ◽  
Natural Vibration ◽  
Natural Vibration Frequency ◽  
Natural Vibrations ◽  
Natural Oscillations ◽  
Element Analysis ◽  
Vibration Diagnostics ◽  
Polyethylene Pipes ◽  
Flat Base

When a pipeline is subjected to an external influence that can affect the frequency of its natural vibrations, the parameters of its natural vibrations change, which increases the measurement error, and often simply distorts the results of vibration control. For pipelines, such an impact may be the influence of the soil when pipelines are laid without a channel. Different types of soil affect the change in the natural vibration frequency of the pipeline in different ways.The purpose of the article is to analyze the influence of various types of soils on the parameters of natural vibrations of the pipeline. The aim of the study was to theoretically confirm the dependence of the change in the frequency of vibration of the pipeline under the influence of soil.A modal analysis of natural oscillations of 5 polyethylene pipelines was performed. As initial data, it is assumed that the design pipeline is laid in a trench with inclined walls, with the slope laid on a flat base at a depth of 2.5 m. The calculations were performed in the ANSYS finite element analysis software package. In order to build a mathematical model, the degree of soil impact on pipelines is determined by studying the vertical and lateral pressure of the soil on the above pipelines, and the natural vibrations of pipelines are analyzed.The results of the modal analysis for polyethylene pipes with a laying scheme with inclined walls and different soils (gravel sands, coarse and medium-sized; heavy clays) are presented. The soils were chosen that are the most common on the territory of Russia.Thus, the obtained dependence of the degree of influence of different soil on the natural frequencies of pipelines significantly increases the reliability of vibration diagnostics of buried communications, can facilitate the work on its organization and allow determining long-term forecasts of pipeline operation.

Mode Analysis and Study of Sunjiagou Aqueduct

2014 ◽  
Vol 912-914 ◽  
pp. 911-914
Author(s):  
Cai Ying Chen ◽  
Ke Lun Wei ◽  
Ya Fei Zhu
Keyword(s):  
Seismic Design ◽  
Vibration Frequency ◽  
Natural Vibration ◽  
Vibration Mode ◽  
Added Mass ◽  
Mode Analysis ◽  
Natural Vibration Frequency ◽  
Analysis Software ◽  
Element Analysis ◽  
The Finite Element Analysis

This paper mainly adopts the finite element analysis software ANSYS to calculate and analyze the dynamic characteristic of aqueduct structure,using added mass method to deal with interaction between water and aqueduct wall, and get the natural vibration frequency and main vibration mode of U-shaped aqueduct in different water depth. The calculation result shows that water has a small effect on the vibration mode of aqueduct structure, but has a greater influence on the natural vibration frequency of aqueduct structure; natural vibration frequency of aqueduct structure decreases with the depth deepening. The research results provide the basis for the seismic design and protection of Sunjiagou aqueduct.

Design Research of Steel Pipe Combination of Angle Steel Tower of XiYue 220kV Cross Section

2013 ◽  
Vol 470 ◽  
pp. 408-411 ◽  
Author(s):  
Yan Zhong Ju ◽  
Xiao Xu Fu ◽  
Neng Xian Zeng
Keyword(s):  
Finite Element Analysis ◽  
Cross Section ◽  
Design Research ◽  
Axial Stress ◽  
Steel Pipe ◽  
Stress Difference ◽  
Analysis Software ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Angle Steel

Given the path situation of Xiyue substation 220kV four outlets project crossing Shunde waterway section,this article applies of Dao Heng tower full stress analysis software and the finite element analysis software ANSYS to two steel pipe combination of angle steel towers to carry on design research,contrast axial stress of two kinds of software,analyse the reasons of axial stress difference.

Research on the Piezoelectric Ultrasonic Actuator Applied to SFSS

2015 ◽  
Author(s):  
Y. J. Tang ◽  
Z. Yang ◽  
X. J. Wang ◽  
J. Wang
Keyword(s):  
Natural Vibration ◽  
Structural Parameters ◽  
Laser Vibrometer ◽  
Vibration Modes ◽  
Element Analysis ◽  
Linear Type ◽  
Frequency Sweep ◽  
The Finite Element Analysis ◽  
Frequency Sweep Test ◽  
Overall Performance

This paper presents an investigation of a novel linear-type piezoelectric ultrasonic actuator for application in a Smart Fuze Safety System (SFSS). Based on the requirements of SFSS, the structural parameters of the proposed piezoelectric ultrasonic actuator are determined by fuze arming mode. Moreover, sensitivity analysis of the structural parameters to the frequency consistency is conducted using FEM software, after which the optimal dimensions are obtained with two close natural vibration frequencies. To validate the results of FEM, the frequency sweep tests of the piezoelectric ultrasonic actuator are performed to determine the motor’s actual working mode frequencies with PSV-300-B Doppler laser vibrometer system. Furthermore, the results of frequency sweep test are compared with that of the finite element analysis, and further verified by impedance analyzer. To investigate the overall performance of the piezoelectric ultrasonic actuator, vibration modes of actuator’s stator, output speed and force of the piezoelectric ultrasonic actuator are tested. The experimental results show that the output speed and force of the actuator can reach 88.2 mm/s and 2.3N respectively, which means that piezoelectric ultrasonic actuator designed in this paper can meet the demands of the SFSS.

The Application of BESO in Vibration Damping of Ship Plate

2013 ◽  
Vol 572 ◽  
pp. 185-188 ◽  
Author(s):  
Xiao Yan Teng ◽  
Jia Shan Han ◽  
Liang Peng
Keyword(s):  
Natural Vibration ◽  
Target Function ◽  
Vibration Damping ◽  
Natural Vibration Frequency ◽  
Constraint Condition ◽  
Evolutionary Structural Optimization ◽  
Damping Material ◽  
Reasonable Result ◽  
Beso Method ◽  
Original Amount

Based on the bi-directional evolutionary structural optimization (BESO), the method of determining the adhesion position of the damping material is proposed in this paper, which is applicable to the vibration damping of ship plate. In this method, the needed amount of damping material is taken as the constraint condition, and the maximization of one natural vibration frequency of the structure is taken as the target function. A thin plate structure with both ends constraints has been taken as an example to get the best topology structure of its adhesion damper by taking the BESO method. The result of optimization shows that it still meets the damping requirements when the needed amount of damping material decreases by about 50% of the original amount. The reasonable result demonstrates the effectiveness and engineering value of the method.

Study on the Influence of Reactor Core Structure on Reactor Natural Vibration Frequency

2021 ◽  
Author(s):  
Yuan Zhou ◽  
Tian Tian ◽  
Xiongfei Yu ◽  
Ran Ren ◽  
Liangcai Zhou ◽  
...  
Keyword(s):  
Vibration Frequency ◽  
Natural Vibration ◽  
Reactor Core ◽  
Core Structure ◽  
Natural Vibration Frequency

Simplified characteristics of active magnetic bearings

2002 ◽  
Vol 216 (5) ◽  
pp. 623-628 ◽  
Author(s):  
D J Peel ◽  
C M Bingham ◽  
Y Wu ◽  
D Howe
Keyword(s):  
Natural Vibration ◽  
Magnetic Bearing ◽  
Active Magnetic Bearing ◽  
Viscous Damping ◽  
Vibration Frequencies ◽  
Active Magnetic Bearings ◽  
Complex Dynamic ◽  
Speed Range ◽  
Constant Coefficients ◽  
System Characteristics

Traditionally, active magnetic bearing (AMB) systems are designed as an integral component of machines having generally complex dynamic characteristics. An AMB supported rotor has been tested over a speed range that included system natural vibration frequencies. A linear stiffness and viscous damping AMB characteristic with constant coefficients was identified which was independent of the overall system characteristics and which can thus provide simple and transferable data for a machine designer.

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