scholarly journals Analysis of the Deep Sea Mining Pipe Transverse Vibration Characteristics Based on Finite Element Method

2021 ◽  
Vol 2021 ◽  
pp. 1-20
Author(s):  
Linjing Xiao ◽  
Qiang Liu
Keyword(s):  
Transverse Vibration ◽  
Deep Sea ◽  
Vibration Reduction ◽  
Beam Model ◽  
Constant Acceleration ◽  
Vibration Intensity ◽  
Damping Effect ◽  
Acceleration And Deceleration ◽  
Reduction Effect ◽  
Small Acceleration

This paper analyzes the transverse vibration laws of 5000 m ladder-shaped mining pipe under different towing velocities and accelerations in the ocean, thinking of the pipe as the beam model, discretized based on the FEM. The algorithm is used to solve the problem to obtain the transverse vibration law. The research shows that the mining pipe overall transverse vibration trend decreases first and then increases, the minimum vibration value occurs at 3000 m, and the maximum occurs at the top. Increasing the towing velocity, acceleration, and ore bin weight will increase the transverse vibration value. The vibration intensity produced by the same acceleration in the constant acceleration and deceleration stages is different, and the damping effect after adding the same damping is also different. In the range of 0.01 m/s2–0.1 m/s2, the vibration reduction effect after adding damping in the constant deceleration stage is more significant, and in the range of 0.1 m/s2-0.2 m/s2, the vibration reduction effect after adding damping in the constant acceleration stage is more significant. In the stage of the constant acceleration or deceleration, when adding the same damping, the vibration intensity generated by the large acceleration is still far greater than the vibration intensity generated by the small acceleration, so the mining ship should keep the small acceleration for towing motion.

scholarly journals Seismic Response and Vibration Reduction Analysis of Suspended Structure under Wave Passage Excitation

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Wenhua Cai ◽  
Bujun Yu ◽  
Fajong Wu ◽  
Jianhua Shao
Keyword(s):  
Seismic Response ◽  
Wave Velocity ◽  
Vibration Reduction ◽  
Shaking Table ◽  
Dynamic Responses ◽  
Uniform Motion ◽  
Acceleration Response ◽  
Maximum Acceleration ◽  
Damping Effect ◽  
Suspended Structure

In order to study the influence of traveling wave effect on the seismic response and damping effect of suspended structure, a series of shaking table tests of the 1 : 20 suspended structure have been carried out to compare and analyze the dynamic responses of suspended structures under two points and a consistent input. The vibration damping effect and vibration reduction law of suspended structure are discussed at different apparent wave velocity and in the different connection. The research shows that the damping suspended structure has a good damping effect, and the amplitude reduction of the top displacement peak response is up to 15%, which corresponds to smaller apparent velocities. Moreover, the upper bound of the maximum acceleration response at the structures’ top under nonuniform input motions equals that of the uniform motion. However, there is a hysteresis in the acceleration response under wave travelling excitations, and the smaller the apparent wave velocity, the more obvious the hysteresis.

scholarly journals Experimental Study on the Vibration Control Effect of Long Elastic Sleeper Track in Subways

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Xiaopei Cai ◽  
Dacheng Li ◽  
Yanrong Zhang ◽  
Qian Miao ◽  
Rixin Cui
Keyword(s):  
Vibration Reduction ◽  
Field Tests ◽  
Urban Rail Transit ◽  
Control Effect ◽  
Tunnel Wall ◽  
Vibration Effect ◽  
Urban Rail ◽  
Vertical Displacements ◽  
Curved Track ◽  
Reduction Effect

The vibration effect of urban rail transit has gained attention from both academia and the industry sector. Long Elastic Sleeper Track (LEST) is a new structure for vibration reduction which has recently been designed and applied to Chinese subways. However, little research has been devoted to its vibration reduction effect. In this study, field tests were conducted during peak transit hours on Beijing Subway Line 15 to examine the vibration reduction effects of the common ballastless track and LEST on both straight and curved sections. The results demonstrate that although LEST increases the wheel-rail vertical forces, rail vertical displacements, and rail accelerations to some extent, these effects do not threaten subway operational safety, and vibrations of track bed and tunnel wall are positively mitigated. LEST has an obvious vibration reduction effect at frequencies above 40 Hz. In straight track, the vibration of bottom of the tunnel wall measured in one-third octave bands is reduced by 10.52 dB, while the vibration at point on the tunnel wall at 1.5 m height is reduced by 9.60 dB. For the curved track, the vibrations at those two points are reduced by 9.35 dB and 8.44 dB, respectively. This indicates that LEST reduces vibrations slightly more for the straight track than for the curved track.

Changes in Floor Impact Sound Insulation Performance with Time

2015 ◽  
Vol 752-753 ◽  
pp. 698-701
Author(s):  
Kyoung Woo Kim ◽  
Jun Oh Yeon ◽  
Kwan Seop Yang
Keyword(s):  
Physical Characteristic ◽  
Dynamic Stiffness ◽  
Vibration Reduction ◽  
Sound Insulation ◽  
Degree Of Reduction ◽  
Floor Structure ◽  
Reduction Effect ◽  
Sound Reduction ◽  
Insulation Performance

Floating floor structures installed with resilient materials are commonly used to reduce sound from floor impacts. Resilient materials minimize the transmission of vibrations by absorbing shock vibrations occurring on the upper part. The floor impact sound reduction performance of resilient materials is related to the dynamic stiffness, which is a physical characteristic of materials. However, the dynamic stiffness varies according to the increase in the loading time of the load that is installed on the upper part of resilient materials. The dynamic stiffness values increase with an increase in the loading time; an increased dynamic stiffness value decreases the vibration reduction effect. The present study focuses on a floor structure installed with resilient materials, and identifies the degree of reduction in floor impact sound insulation performance with the elapse of time. The insulation of sound from lightweight impact sound decreased with the elapse of time, whereas the heavyweight impact sound did not show significant changes.

SEISMIC CONTROL OF MULTI-ADJACENT-BUILDING SYSTEMS

2010 ◽  
Vol 10 (01) ◽  
pp. 21-35 ◽  
Author(s):  
L. ZOU ◽  
J. W. BUTTERWORTH ◽  
X. MA
Keyword(s):  
Vibration Reduction ◽  
Equation Of Motion ◽  
Seismic Control ◽  
Building Model ◽  
Controlled Systems ◽  
Adjacent Structures ◽  
Adjacent Building ◽  
Building Systems ◽  
Reduction Effect ◽  
Influential Parameters

Proposed herein is a new vibration-reduction technique for multi-adjacent-building systems subjected to earthquake excitations. Based on a three-building model, three different connecting methods are presented for reducing the seismic response of the multi-building system. After the equation of motion is derived, a numerical example is employed to demonstrate the seismic performances of the controlled systems. The vibration-reduction mechanism, the vibration-reduction effect, and the influential parameters are also studied. Numerical results show that the method of coupling adjacent structures is a viable and attractive vibration-reduction strategy for seismically excited structures.

The Experimental Study of the Magnetic Fluid Damper Based on the Principle of Second-Order Buoyancy

2012 ◽  
Vol 512-515 ◽  
pp. 1459-1463 ◽  
Author(s):  
Yi Ding ◽  
De Cai Li ◽  
Qing Lei Wang ◽  
Hai Na Zhang ◽  
Zhi Li Zhang
Keyword(s):  
Experimental Study ◽  
Magnetic Fluid ◽  
Second Order ◽  
Test Rig ◽  
Damping Effect ◽  
Fluid Damper ◽  
Reduction Effect ◽  
Set Up ◽  
The Relationship

Two different structure of dampers based on the principle of second-order buoyancy were designed in this paper. In order to verify the reduction of the vibration, a test rig was set up. On the test rig, the reduction effect of two different dampers was studied by adjusting the amount of the magnetic fluid. The experiment results indicate the relationship between the damping effect of magnetic fluid damper and the amount of magnetic fluid and this analysis result is benefit to the design of the dampers.

Projected Phase-Plane Switching Curves for Vibration Reduction Filters With Negative Amplitudes

2014 ◽  
Vol 136 (5) ◽  
Author(s):  
Abhishek Dhanda
Keyword(s):  
Closed Form ◽  
Real Time ◽  
Phase Plane ◽  
Closed Loop ◽  
Vibration Reduction ◽  
Shaping Filter ◽  
Negative Impulse ◽  
Acceleration And Deceleration ◽  
Analytical Expressions ◽  
Loop Scheme

In this paper, we extend the phase-plane based closed-loop scheme of implementing commands shaped with vibration-reduction filters. A generalized shaping filter is considered in this work which can have negative impulse intensities and different acceleration and deceleration limits. Switching conditions are derived in terms of the filter parameters for both convolution-based and closed-form based shaping techniques. Analytical expressions are provided for the switching curves and various schemes are discussed for selecting appropriate phase-planes and implementing shaped-commands on real-time servomechanisms.

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