scholarly journals Vertical Natural Vibration Modes of Ballasted Railway Track

2018 ◽  
Author(s):  
Akira Aikawa
Keyword(s):  
Natural Vibration ◽  
Railway Track ◽  
Vibration Modes

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.

scholarly journals Vibration of thin cylindrical shells on an elastic foundation coupled with multiple discrete stiffnesses

2018 ◽  
Vol 237 ◽  
pp. 01011 ◽  
Author(s):  
Fuchun Yang ◽  
Wenlei Qiu
Keyword(s):  
Natural Frequency ◽  
Elastic Foundation ◽  
Natural Vibration ◽  
Cylindrical Shells ◽  
Vibration Modes ◽  
Governing Equations ◽  
Vibration Properties ◽  
Shear Modes ◽  
External Forces ◽  
Circumferential Wave

Vibration properties of thin cylindrical shells on an elastic foundation coupled with multiple discrete stiffnesses were investigated. The discrete stiffnesses were modelled as external forces. Hamilton’s principle was applied to deduce the governing equations. To study the natural vibration properties, the wave-like solutions were applied. Then the governing equations were discretized in matrix form to obtain the eigenvalues. The properties of natural frequencies and vibration modes of thin cylindrical shells were studied. The results illustrate that each natural frequency of cylindrical shells is mainly dominated by one vibration mode, that is, flexural, longitudinal and shear modes. The natural frequency will get closer with the increase of circumferential wave numbers. The influences of several parameters to vibration properties of cylindrical shells were also investigated.

Comprehensive Dynamic Model and Vibration Characteristics of Step-Type Compound Planetary Gear Sets

2011 ◽  
Vol 308-310 ◽  
pp. 1923-1928
Author(s):  
Fu Chun Yang ◽  
Xiao Jun Zhou ◽  
Ming Xiang Xie
Keyword(s):  
Dynamic Model ◽  
Natural Vibration ◽  
Natural Frequencies ◽  
Planetary Gear ◽  
Vibration Characteristics ◽  
Vibration Modes ◽  
Shape Distribution ◽  
Type Compound ◽  
Planetary Gear Sets ◽  
Step Type

Step-type compound planetary gear sets are widely applied in vehicle systems. Comprehensive dynamic model of step-type compound planetary gear sets, which includes translational, rotational vibrations and static transmission errors, was established. Natural vibration characteristics of the system, such as natural frequencies and vibration modes, were analyzed. Belt shape distribution characteristics of its natural frequencies was researched. According to vibration characteristics of both central components and planets, natural vibration modes of the system are classified into three types: central components translational vibration and planets random vibration, central components rotational vibration and planets identical vibration, central components static and adjacent planets reverse vibration mode.

Natural Vibration Analysis of High-Speed Railway Slab Tracks under Rail Longitudinal Force

2013 ◽  
Vol 706-708 ◽  
pp. 1443-1449 ◽  
Author(s):  
Yi Shi Guo ◽  
Zu Jun Yu ◽  
Hong Mei Shi
Keyword(s):  
High Speed ◽  
Natural Vibration ◽  
Longitudinal Force ◽  
Frequency Equation ◽  
Railway Track ◽  
High Speed Railway ◽  
Slab Track ◽  
Specific Effects ◽  
Coupling Dynamics ◽  
Dynamics Problems

The slab track is the main structure of the high-speed railway track, the Inherent dynamic characteristics of which is of great significance to the research on the Vehicle-Track Coupling Dynamics. The assumptions of the modal function describing the natural vibration of the track is a necessary theoretical basis in analytic and numerical calculations for dynamics problems, which is more in accordance with the real situation, the more likely characteristic estimation are to be accurate. In this paper, with the method of combine matrix, the system characteristic equation of slab-track model is deduced, and the exact analytic formulas of frequency equation and modal function are obtained. Meanwhile the specific effects of the Rail longitudinal force on the vibration performance of the tracks are analyzed through instances. The results show that this approach is an effective analytic method, the solution of which is accurate. And the track parameters can be flexibly initialized, which is especially applicable for the condition of track parameters varying and longitudinal strain with distribution.

FEM Design and Experiment of XY Motion Platform in Flip Chip Machine

2013 ◽  
Vol 278-280 ◽  
pp. 7-13
Author(s):  
Lu Fan Zhang ◽  
Zhi Li Long ◽  
Ji Wen Fang ◽  
Jian Dong Cai ◽  
Long Sheng Nian
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Stress Distribution ◽  
Flip Chip ◽  
Natural Vibration ◽  
Vibration Modes ◽  
Motion Platform ◽  
Measuring Device ◽  
Precise Positioning ◽  
Flip Chip Packaging

XY motion platform in flip chip machine plays a key module to achieve precise positioning in the process of flip chip packaging. The paper presents an XY motion platform structure. The static and modal characteristics of the XY motion platform were calculated by finite element method, and then some important conclusions were obtained. The displacement and stress distribution of XY motion platform were disclosed. The relevant change trends of displacement and stress under the different load were investigated and the first four natural vibration modes of the XY motion platform were obtained. In the experiment, the vibration behavior was measured by a non-contact laser measuring device. The experiments verify the correctness of the simulation of the XY motion platform. These results can help improve the reliability of the XY motion platform.

scholarly journals Algorithm for Tracking Natural Vibration Modes Using Image Operation

2009 ◽  
Vol 3 (1) ◽  
pp. 82-94 ◽  
Author(s):  
Hirohisa ENOMOTO ◽  
Shigeru SAKAMOTO
Keyword(s):  
Natural Vibration ◽  
Vibration Modes

scholarly journals Gait Patterns of Quadrupeds and Natural Vibration Modes

2008 ◽  
Vol 2 (6) ◽  
pp. 1316-1326 ◽  
Author(s):  
Yutaka KURITA ◽  
Yuichi MATSUMURA ◽  
Shinichi KANDA ◽  
Hironao KINUGASA
Keyword(s):  
Natural Vibration ◽  
Vibration Modes ◽  
Gait Patterns

scholarly journals Dynamic Characteristics Analysis and Experimental Verification of Long Span Suspension Bridge

2021 ◽  
Vol 272 ◽  
pp. 01019
Author(s):  
Guojun Yang ◽  
Qiwei Tian ◽  
Guangwu Tang ◽  
Longlong Li ◽  
Su Ye ◽  
...  
Keyword(s):  
Dynamic Characteristics ◽  
Vibration Frequency ◽  
Natural Vibration ◽  
Structural Parameters ◽  
Great Influence ◽  
Suspension Bridge ◽  
Natural Vibration Frequency ◽  
Vibration Modes ◽  
Dead Load ◽  
Long Span

The dynamic characteristics of long-span suspension bridges are complex. The natural vibration frequency is changed with different structural parameters, and the sensitivity to different parameters is different. In order to solve this problem, the spatial model of a long-span suspension bridge was established by using finite element software, and the first 20 natural vibration periods, natural vibration frequencies and vibration modes were analyzed and calculated. The accuracy of the obtained natural vibration frequency data was verified through field tests. Finally, based on the model, the stiffness of structural components is studied by one -factor-at-one-time, and the influence of various variables on the frequency and mode of a certain mode is studied by one-factor-at-one-time method. The results show that different structural parameters have different effects on the vibration frequency. When the stiffness of stiffening girder and main tower is changed, with the increase of stiffness, the variation of frequency mostly presents an upward trend, and the range is large. With the change of the secondary dead load, most of the frequencies decrease first and then tend to be stable. It can be seen from the field test results that the vibration shapes and frequencies measured by numerical simulation and test are close to each other, which can meet the requirements of engineering precision. The stiffness of the main cable and the main tower has a great influence on the modes and periods corresponding to them. The increase of the secondary dead load can reduce the natural vibration frequency of the suspension bridge, but it is not unlimited to increase the secondary dead load to reduce the frequency. The stiffness of the stiffening girder has a great influence on the frequency of the suspension bridge. When the bending stiffness of the stiffening girder increases to 3 times of the original one, the order of vibration modes of the structure will change. The research results can provide references for structural design and dynamic parameter adjustment of long-span suspension bridge.

Dynamic Response of Base Isolated Rotational Shell with Edge Beam and Fuzzy Vibration Control of the Shell

1997 ◽  
Vol 12 (3-4) ◽  
pp. 173-179 ◽  
Author(s):  
Kiyoshi Shingu ◽  
Kiyotoshi Hiratsuka
Keyword(s):  
Dynamic Response ◽  
Vibration Control ◽  
Control Systems ◽  
Seismic Isolation ◽  
Natural Vibration ◽  
Natural Frequencies ◽  
Fuzzy Theory ◽  
Vibration Modes ◽  
Rotational Shell ◽  
Seismic Forces

Seismic isolation and fuzzy vibration control systems, which consist of a shell with an edge beam which has springs and variable dampers between the edge beam and the ground, are suggested by one of the authors. In this paper, natural vibration modes and natural frequencies of base isolated rotational shells with edge beams are shown. When the shell shakes due to vertical seismic forces, the seismic isolated system is implemented. As a result, stresses in the shell are significantly reduced. Furthermore, vibration control of the shell is carried out. Then the damping ratios are adjusted by the fuzzy theory, and stresses in the shell are further reduced.

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