scholarly journals Transverse Vibrations of Underground Pipelines with Different Interaction Laws of Pipe with Surrounding Soils

2021 ◽  
Vol 264 ◽  
pp. 02035
Author(s):  
Batir Mardonov ◽  
Ekaterina An ◽  
Shuhrat Shojalilov ◽  
Yakutxon Khakimova ◽  
Gulchexra Ismoilova
Keyword(s):  
Resonant Frequency ◽  
Computational Model ◽  
Vibration Mode ◽  
Computational Studies ◽  
Resonant Vibration ◽  
Stiffness Coefficient ◽  
Seismic Effects ◽  
Underground Pipelines ◽  
Transverse Vibrations

Studies on the effect of changing the stiffness coefficient along the length of the pipeline on its resonant vibration mode are considered in the paper. A computational model of transverse vibrations of the pipeline located in soil with different properties is created. Theoretical and computational studies to solve the problems of stability of underground pipelines located in the soils with different properties under seismic effects are carried out. It is revealed that the vibratory process of the pipeline can be realized at frequencies close to resonance. The results of the study are presented as curves of distribution of displacements of pipeline sections along the length at dimensionless frequencies. When the pipeline vibrates with a frequency close to the resonant frequency, the displacements of pipeline sections can take very large values. It is shown that at frequencies close to resonance, the values of moments can be large in the pipeline sections, which are the reasons for the loss of pipeline stability.

Stress and Vibration Analysis of Motor Back Plate in HDD

2011 ◽  
Vol 275 ◽  
pp. 97-100 ◽  
Author(s):  
Geun Sub Heo ◽  
Oh Hyun Kang ◽  
Cheol Woo Park ◽  
Sang Ryong Lee ◽  
Choon Young Lee
Keyword(s):  
Resonant Frequency ◽  
High Speed ◽  
Vibration Mode ◽  
Hard Disk Drives ◽  
Mode Analysis ◽  
Design Parameters ◽  
Disk Drives ◽  
Ansys Software ◽  
Back Plate ◽  
Plate Shape

In the present study, we have simulated stress characteristics and vibration modes in the back plate of head-stack driving motor of 2.5 inch small sized hard disk drives (HDDs). The magnets in head-stack driving motor have large magnetic fields, and therefore, the resulting large force may induce fracture and deformation in the back plate of the motor. Since the high-speed motion of head-stack motor generates high frequency vibration, we analyzed the vibration mode to avoid resonant frequency. ANSYS software was used in this study to check the deformation of back plate with the following design parameters: thickness of plate, the number of support beams, and the width of support beams. From the vibration mode analysis, we obtained a stable plate shape whose operating frequency is off the resonant frequency.

scholarly journals INFLUENCE OF INCONSTANT DISTRIBUTION OF DEADWOOD BEARING STIFFNESS COEFFICIENTON NATURAL FREQUENCY OF THE SHAFT TRANSVERSE VIBRATIONS

2019 ◽  
pp. 89-96
Author(s):  
Guriy Kushner ◽  
Victor Andreevich Mamontov
Keyword(s):  
Differential Equation ◽  
Distribution Function ◽  
Uniform Distribution ◽  
Natural Frequency ◽  
Stiffness Coefficient ◽  
Propeller Shaft ◽  
Shaft Length ◽  
Slide Bearing ◽  
Transverse Vibrations ◽  
Stiffness Distribution

One of the most significant factors affecting the natural frequency of transverse vibrations of shaft-slide bearing systems is the stiffness coefficient of the slide bearing. The need to consider the influence of heterogeneity of stiffness coefficient of the bearing on its natural frequency is caused by the fact that when the bearing is worn, the modulus of longitudinal elasticity of the material changes, and since the bearing wears unevenly, the non-uniform distribution of the stiffness coefficient occurs. The problem of determining the natural frequency of transverse vibrations of a ship propeller shaft based on the foundation with a variable stiffness coefficient along the length has been studied. The differential equation of the propeller shaft vibrations written taking into account the stiffness coefficient variable along the shaft length is considered. It has been noted that, in the general case, this equation is a fourth-order partial differential equation and cannot be integrated in quadratures for an arbitrary stiffness distribution function along the shaft length. A numerical-analytical method for determining the natural frequency of a system based on approximation of the stiffness distribution function by a piecewise-linear function is proposed. The method is applied to calculate the natural frequencies of the pipeline section taking into account the functions describing the change in the stiffness coefficient. The proposed method allows to consider the section of the shafting enclosed in the stern bearing, subject to the non-uniform distribution of the stiffness coefficient of the bearing, and is the basis for improving the accuracy of finding the true natural frequency of transverse vibrations of the shafting.

Piezoelectric Properties in Textured Ceramics of SrBi2Nb2O9

2006 ◽  
Vol 320 ◽  
pp. 15-18 ◽  
Author(s):  
Takuya Sawada ◽  
Hirozumi Ogawa ◽  
Masahiko Kimura ◽  
Kosuke Shiratsuyu ◽  
Akira Ando
Keyword(s):  
Resonant Frequency ◽  
Grain Growth ◽  
Coupling Coefficient ◽  
Remanent Polarization ◽  
Vibration Mode ◽  
Piezoelectric Properties ◽  
Templated Grain Growth ◽  
Orientation Degree ◽  
Mechanical Coupling ◽  
Textured Ceramics

A study has been done for the piezoelectric properties in texured ceramics of SrBi2Nb2O9 (SBN) fabricated by the templated grain growth (TGG) method. Remanent polarization along to the stacking direction increased with the orientation degrees. That corresponds to the increases in electro-mechanical coupling coefficient with orientation degree. The temperature coefficient of the resonant frequency (TCF) in thickness sheer vibration mode changed from negative to positive with increasing orientation degrees, and an excellent TCF of -0.4 ppm/°C was obtained for the specimen with an orientation degree of 76%.

Nonlinear Transverse Vibrations of a Spinning Disk

1964 ◽  
Vol 31 (1) ◽  
pp. 72-78 ◽  
Author(s):  
Jerzy L. Nowinski
Keyword(s):  
Large Amplitude ◽  
Close Agreement ◽  
Vibration Mode ◽  
Linear Case ◽  
Field Equations ◽  
Spinning Disk ◽  
Transverse Vibrations ◽  
Von Karman ◽  
Large Amplitude Vibrations ◽  
Von Kármán

Using the von Karman field equations, large amplitude vibrations of a spinning disk are analysed. For definiteness, the disk is assumed to be free, and its deflection is represented by a two-term polynomial. A vibration mode associated with two nodal diameters is studied in more detail. A familiar phenomenon of a decreasing period of vibration with an increasing amplitude is corroborated. The results specialized to the linear case show a close agreement with the classical results of Lamb and Southwell. The dependence of the membrane stresses on the amplitude of vibration and the velocity of spin is discussed.

scholarly journals A Dynamic Model for Ice-Induced Vibration of Structures

2006 ◽  
Author(s):  
Guojun Huang ◽  
Pengfei Liu
Keyword(s):  
Resonant Frequency ◽  
Dynamic Model ◽  
Present Model ◽  
Field Observations ◽  
Resonant Vibration ◽  
Crushing Strength ◽  
Ice Velocity ◽  
Ice Failure ◽  
Lock In ◽  
Ice Induced Vibration

A dynamic model for the ice-induced vibration (IIV) of structures is developed in the present study. Ice properties have been taken into account, such as the discrete failure, the dependence of the crushing strength on the ice velocity and the randomness of the ice failure. The most important prediction of the model is to capture the resonant frequency lock-in, which is analogue to that in the vortex-induced vibration (VIV). Based on the model, the mechanism of resonant IIV is discussed. It is found that the dependence of the ice crushing strength on the ice velocity plays an important role in the resonant frequency lock-in of IIV. In addition, an intermittent stochastic resonant vibration is simulated from the model. These predictions are supported by the laboratory and field observations reported. The present model is more productive than the previous models of IIV.

scholarly journals Diffusion of kinesin motors on cargo can enhance binding and run lengths during intracellular transport

2019 ◽  
Author(s):  
Matthew Bovyn ◽  
Babu Reddy ◽  
Steven Gross ◽  
Jun Allard
Keyword(s):  
Computational Model ◽  
Molecular Motors ◽  
Lipid Droplets ◽  
Intracellular Transport ◽  
Control Point ◽  
Computational Studies ◽  
Organizational Changes ◽  
Surface Mobility ◽  
Viscosity Effects ◽  
Run Lengths

Cellular cargos, including lipid droplets and mitochondria, are transported along microtubules using molecular motors such as kinesins. Many experimental and computational studies of cargos with rigidly attached motors, in contrast to many biological cargos that have lipid surfaces that may allow surface mobility of motors. We extend a mechanochemical 3D computational model by adding coupled-viscosity effects to compare different motor arrangements and mobilities. We show that organizational changes can optimize for different objectives: Cargos with clustered motors are transported efficiently, but are slow to bind to microtubules, whereas those with motors dispersed rigidly on their surface bind microtubules quickly, but are transported inefficiently. Finally, cargos with freely-diffusing motors have both fast binding and efficient transport, although less efficient than clustered motors. These results suggest that experimentally observed changes in motor organization may be a control point for transport.

S1350102 A continuously cell culturing method by using resonant vibration mode

2015 ◽  
Vol 2015 (0) ◽  
pp. _S1350102--_S1350102-
Author(s):  
Yuta KURASHINA ◽  
Chikahiro IMASHIRO ◽  
Kenjiro TAKEMURA ◽  
Shogo MIYATA ◽  
Jun KOMOTORI ◽  
...  
Keyword(s):  
Vibration Mode ◽  
Resonant Vibration ◽  
Cell Culturing

Measurement and Visualization of Dynamics of Piezoelectric Microcantilever

2010 ◽  
Vol 437 ◽  
pp. 30-34
Author(s):  
Wei Jie Dong ◽  
Meng Wei Liu ◽  
Cui Yan
Keyword(s):  
Resonant Frequency ◽  
Optical System ◽  
Light Microscope ◽  
Vibration Mode ◽  
Ccd Camera ◽  
Mode Shapes ◽  
Micro Structure ◽  
Resonant Frequencies ◽  
Video Card ◽  
Piezoelectric Microcantilever

Methods for measuring the resonant frequencies and visualizing the motion of the Pb(Zr0.5Ti0.5)O3 microcantilever are investigated. Considering the two-segment structure of the microcantilever, a self-exiting self-sensing method is proposed to obtain the fundamental resonant frequency. An optical system consisting of light microscope, CCD camera and video card is established to visualize the first two vibration mode shapes. The theoretical, measured and visualized first resonance of one micocantilever is 17.28 kHz, 17 kHz and 17.8 kHz, respectively. A theoretical second resonance of 84.16 kHz is seen at 71.9 kHz. The proposed method is valid for measuring and visualizing low resonances of active micro structure.

scholarly journals ASSESSMENT OF IMPACT OF STERN BEARING MATERIAL RIGIDNESS ONTO OPERABILITY OF THE SHIP SHAFT LINE

2017 ◽  
pp. 80-87
Author(s):  
Igor Olegovich Razov ◽  
Guriy Kushner ◽  
Victor Andreevich Mamontov ◽  
Aleksey Aleksandrovich Khalyavkin
Keyword(s):  
Elastic Support ◽  
Stiffness Coefficient ◽  
Propeller Shaft ◽  
Bearing Material ◽  
Shaft Line ◽  
Transverse Vibrations ◽  
Bearing Stiffness ◽  
Design Diagram ◽  
The Impact ◽  
Constant Section

The article considers the dependence of the ship shaft line efficiency on a stiffness coefficient of the material, which stern bearings are made of. The obtained values of a stiffness coefficient used in calculating transverse vibrations of the ship shaft line have been analyzed. The influence of a stiffness coefficient on the value of eigen frequency of transverse vibrations of a propeller shaft has been studied. The design diagram of a propeller shaft is proposed where the propeller shaft is shown as a beam of constant section, which rests upon a hinged immovable and elastic support with a disk on the end. The elastic support models the fodder stern bearing. The influence of the shape of contact of a propeller shaft with a stern bearing onto the load distribution has been estimated. The technique of determining a stiffness coefficient subject to mechanical and geometric parameters of a ship shaft line and its stern bearings has been offered. The impact of a ship shaft line onto the stressed state of the stern bearings and their draft has been studied. The equation of determining a bearing stiffness coefficient has been obtained. There have been given numerical values of a stiffness coefficient of the stern bearing material for certain types of ships.

scholarly journals ACTIVE VIBRATIONAL CONTROL OF FLEXIBLE MANIPULATOR USING FILTERED-X LMS ALGORITHM

2017 ◽  
Keyword(s):  
Vibration Control ◽  
Vibration Mode ◽  
Notch Filter ◽  
Lms Algorithm ◽  
Flexible Manipulator ◽  
Resonant Vibration ◽  
Joint Angles ◽  
Adaptive Notch Filter ◽  
Vibrational Control ◽  
System Input

This paper describes the vibration control of a flexible manipulator using Filtered-x LMS algorithm. In this study adaptive notch filter is applied to the vibration control of a flexible manipulator model. The adaptive notch filter is designed to estimate multiple vibration mode frequencies of the flexible manipulator and to minimize the effect of vibration. The filtered-x LMS algorithm is applied to make the root strain error and the system input as close to minimization as possible. In the process, the adaptive notch filter learns to eliminate the resonant vibration frequencies of the system. The experimental results show that this presented adaptive notch filter system can suppress the vibration of the flexible manipulator and track the desired joint angles.

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