Dynamical Analysis of an Offshore Platform with Vibration Absorbers

2000 ◽  
pp. 23-34
Author(s):  
L. Bevilacqua ◽  
R. B. Battista ◽  
N. F. F. Ebecken
Keyword(s):  
Offshore Platform ◽  
Dynamical Analysis ◽  
Vibration Absorbers

scholarly journals Nonlinear Dynamical Analysis on Four Semi-Active Dynamic Vibration Absorbers with Time Delay

2013 ◽  
Vol 20 (4) ◽  
pp. 649-663 ◽  
Author(s):  
Yongjun Shen ◽  
Mehdi Ahmadian
Keyword(s):  
Time Delay ◽  
Analytical Solutions ◽  
Numerical Solutions ◽  
Dynamical Analysis ◽  
Control Procedure ◽  
Vibration Absorbers ◽  
Nonlinear Dynamical ◽  
Dynamic Vibration ◽  
Approximate Analytical Solutions ◽  
Dynamic Vibration Absorbers

In this paper four semi-active dynamic vibration absorbers (DVAs) are analytically studied, where the time delay induced by measurement and execution in control procedure is included in the system. The first-order approximate analytical solutions of the four semi-active DVAs are established by the averaging method, based on the illustrated phase difference of the motion parameters. The comparisons between the analytical and the numerical solutions are carried out, which verify the correctness and satisfactory precision of the approximate analytical solutions. Then the effects of the time delay on the dynamical responses are analyzed, and it is found that the stability conditions for the steady-state responses of the primary systems are all periodic functions of time delay, with the same period as the excitation one. At last the effects of time delay on control performance are discussed.

Dynamical analysis of the programmed cell death pathway

2007 ◽  
Author(s):  
Luciano Carotenuto ◽  
Vincenza Pace ◽  
Dina Bellizzi ◽  
Giovanna De Benedictis
Keyword(s):  
Cell Death ◽  
Programmed Cell Death ◽  
Dynamical Analysis ◽  
Cell Death Pathway

VIBRATION CONTROL OF SLENDER STRUCTURES WITH OPTIMIZED LIQUID COLUMN VIBRATION ABSORBERS

2019 ◽  
Author(s):  
Jéssica Carolina Barbosa Vieira ◽  
Thiago da Silva ◽  
Carlos Alberto Bavastri
Keyword(s):  
Vibration Control ◽  
Liquid Column ◽  
Vibration Absorbers ◽  
Slender Structures

Tribological and dynamical analysis of a brake pad with multiple blocks for a high-speed train

2019 ◽  
Vol 234 (11) ◽  
pp. 1771-1788
Author(s):  
YK Wu ◽  
JL Mo ◽  
B Tang ◽  
JW Xu ◽  
B Huang ◽  
...  
Keyword(s):  
High Speed ◽  
Wear Behavior ◽  
Dynamical Analysis ◽  
Brake Disc ◽  
Brake Pad ◽  
High Speed Train ◽  
Brake Squeal ◽  
Element Analysis ◽  
Single Block ◽  
Middle Ring

In this research, the tribological and dynamical characteristics of a brake pad with multiple blocks are investigated using experimental and numerical methods. A dynamometer with a multiblock brake pad configuration on a brake disc is developed and a series of drag-type tests are conducted to study the brake squeal and wear behavior of a high-speed train brake system. Finite element analysis is performed to derive physical explanations for the observed experimental phenomena. The experimental and numerical results show that the rotational speed and braking force have important influences on the brake squeal; the trends of the multiblock and single-block systems are different. In the multiblock brake pad, the different blocks exhibit significantly different magnitudes of contact stresses and vibration accelerations. The blocks located in the inner and outer rings have higher vibration acceleration amplitudes and stronger vibration energies than the blocks located in the middle ring.

Finite Element Analysis of the Distributed Vibration Absorbers for Structural Noise Control

2005 ◽  
Author(s):  
Ashwini Gautam ◽  
Chris Fuller ◽  
James Carneal
Keyword(s):  
Finite Element ◽  
Numerical Model ◽  
Base Plate ◽  
Element Model ◽  
Fe Model ◽  
Vibration Absorbers ◽  
Element Analysis ◽  
Poroelastic Media ◽  
Hexahedral Elements ◽  
Component Models

This work presents an extensive analysis of the properties of distributed vibration absorbers (DVAs) and their effectiveness in controlling the sound radiation from the base structure. The DVA acts as a distributed mass absorber consisting of a thin metal sheet covering a layer of acoustic foam (porous media) that behaves like a distributed spring-mass-damper system. To assess the effectiveness of these DVAs in controlling the vibration of the base structures (plate) a detailed finite elements model has been developed for the DVA and base plate structure. The foam was modeled as a poroelastic media using 8 node hexahedral elements. The structural (plate) domain was modeled using 16 degree of freedom plate elements. Each of the finite element models have been validated by comparing the numerical results with the available analytical and experimental results. These component models were combined to model the DVA. Preliminary experiments conducted on the DVAs have shown an excellent agreement between the results obtained from the numerical model of the DVA and from the experiments. The component models and the DVA model were then combined into a larger FE model comprised of a base plate with the DVA treatment on its surface. The results from the simulation of this numerical model have shown that there has been a significant reduction in the vibration levels of the base plate due to DVA treatment on it. It has been shown from this work that the inclusion of the DVAs on the base plate reduces their vibration response and therefore the radiated noise. Moreover, the detailed development of the finite element model for the foam has provided us with the capability to analyze the physics behind the behavior of the distributed vibration absorbers (DVAs) and to develop more optimized designs for the same.

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