scholarly journals A Study on Design and Analysis of Hybrid Vibration Damper with Energy Harvesting and Optimal Damping Effect

2014 ◽  
Vol 95 (2) ◽  
pp. 97-102 ◽  
Author(s):  
T. V. Hanumantha Rao ◽  
M. S. S. Srinivasa Rao ◽  
B. V. Apparao ◽  
K. Satyanarayana
Keyword(s):  
Energy Harvesting ◽  
Vibration Damper ◽  
Damping Effect ◽  
Optimal Damping

Multiple stability and maximum stability in a model population

1975 ◽  
Vol 53 (12) ◽  
pp. 1844-1854 ◽  
Author(s):  
Donald J. McQueen
Keyword(s):  
Numerical Stability ◽  
Equilibrium Points ◽  
Demographic Model ◽  
Natural Mortality ◽  
Demographic Structure ◽  
Stability Range ◽  
Damping Effect ◽  
Optimal Damping ◽  
Maximum Stability ◽  
Multiple Stability

Using a modular demographic model this work attempts to mechanistically explain how multistability levels might occur, to explain how a population might move from one level to another, and to investigate the combination of forces which leads to maximum stability within a local stability range. The work showed that unique stability levels for single populations are created by unique combinations of rates such as birth, natural mortality, emigration, immigration, and interference, and that because these rates depend upon factors such as climate and resource availability, stability levels constantly change and arc constantly chased by the population. The simulations also showed that, as rates changed, stable and unstable equilibrium points approached and met one another causing the population to shift from one stability level to another. The work also suggested that there was an inverse relationship between the numerical stability of the population and the number of feedback forces influencing its demographic structure. Maximum stability was achieved by excluding all but one feedback force, and among the simulations of this type that were performed, natural mortality acting alone produced the optimal damping effect.

Rheology behavior and optimal damping effect of granular particles in a non-obstructive particle damper

2016 ◽  
Vol 364 ◽  
pp. 30-43 ◽  
Author(s):  
Kai Zhang ◽  
Tianning Chen ◽  
Xiaopeng Wang ◽  
Jianglong Fang
Keyword(s):  
Damping Effect ◽  
Optimal Damping ◽  
Granular Particles

Semi-active damping and energy harvesting using an electromagnetic transducer

2017 ◽  
Vol 24 (12) ◽  
pp. 2542-2561 ◽  
Author(s):  
Giovanni Caruso ◽  
Sergio Galeani ◽  
Laura Menini
Keyword(s):  
Energy Harvesting ◽  
Optimal Strategies ◽  
Optimal Choice ◽  
Vibration Damping ◽  
Single Degree Of Freedom ◽  
Electromagnetic Transducer ◽  
Optimal Damping ◽  
Time Optimal ◽  
Active Control Strategy ◽  
The Pontryagin Maximum Principle

This article studies a semi-active control strategy applied to a vibration damping and to an energy harvesting problem. In particular, a single-degree-of freedom oscillating device is considered, comprising a mass connected to the ground by means of a spring, a dashpot and an electromagnetic transducer. The latter component yields a damping contribution which can be easily modulated between a minimum and a maximum value. By applying the Pontryagin maximum principle to the vibration damping problem, it is shown that the time optimal control law consists of a switching of the electromechanical damping contribution between the maximum and the minimum values. The same Principle is then applied to the optimization of the energy harvestable by the same structure under periodic excitation. Differently from the case of vibration damping, the solution of the latter problem can contain both regular phases (during which the optimal choice of the modulated damping is either at its maximum or at its minimum value) and singular phases (during which the optimal damping has smooth variations). Interestingly, it is also shown that when the objective is to dissipate rather than to harvest energy from the device, optimal strategies only consist of regular phases. Both the proposed semi-active strategies are shown to outperform corresponding optimized passive classic solutions, used as a benchmark for comparison.

scholarly journals Damping Effect Coupled with the Internal Translator Mass of Linear Generator-Based Wave Energy Converters

Energies ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 4424
Author(s):  
Yue Hong ◽  
Mikael Eriksson ◽  
Cecilia Boström ◽  
Jianfei Pan ◽  
Yun Liu ◽  
...  
Keyword(s):  
Wave Energy ◽  
Mechanical Design ◽  
Damping Force ◽  
The West ◽  
Linear Generator ◽  
Damping Effect ◽  
Wave Energy Converters ◽  
Optimal Damping ◽  
Vital Factor ◽  
Energy Converters

The damping effect, induced inside the linear generator, is a vital factor to improve the conversion efficiency of wave energy converters (WEC). As part of the mechanical design, the translator mass affects the damping force and eventually affects the performance of the WEC by converting wave energy into electricity. This paper proposes research on the damping effect coupled with translator mass regarding the generated power from WEC. Complicated influences from ocean wave climates along the west coast of Sweden are also included. This paper first compares three cases of translator mass with varied damping effects. A further investigation on coupling effects is performed using annual energy absorption under a series of sea states. Results suggest that a heavier translator may promote the damping effect and therefore improve the power production. However, the hinder effect is also observed and analyzed in specific cases. In this paper, the variations in the optimal damping coefficient are observed and discussed along with different cases.

Electrical vibration damper

1982 ◽  
Vol 129 (5) ◽  
pp. 182 ◽  
Author(s):  
Hiroshi Kurokui ◽  
Michio Nakano
Keyword(s):  
Vibration Damper

Analysis of magneto rheological elastomers for energy harvesting systems

2020 ◽  
Vol 64 (1-4) ◽  
pp. 439-446
Author(s):  
Gildas Diguet ◽  
Gael Sebald ◽  
Masami Nakano ◽  
Mickaël Lallart ◽  
Jean-Yves Cavaillé
Keyword(s):  
Magnetic Field ◽  
Energy Harvesting ◽  
Shear Strain ◽  
Magnetic Induction ◽  
Magnetic Particles ◽  
Homogeneous Magnetic Field ◽  
Electrical Signal ◽  
Harvesting Systems ◽  
Dc Bias ◽  
Magneto Rheological

Magneto Rheological Elastomers (MREs) are composite materials based on an elastomer filled by magnetic particles. Anisotropic MRE can be easily manufactured by curing the material under homogeneous magnetic field which creates column of particles. The magnetic and elastic properties are actually coupled making these MREs suitable for energy conversion. From these remarkable properties, an energy harvesting device is considered through the application of a DC bias magnetic induction on two MREs as a metal piece is applying an AC shear strain on them. Such strain therefore changes the permeabilities of the elastomers, hence generating an AC magnetic induction which can be converted into AC electrical signal with the help of a coil. The device is simulated with a Finite Element Method software to examine the effect of the MRE parameters, the DC bias magnetic induction and applied shear strain (amplitude and frequency) on the resulting electrical signal.

Simply supported FPEDs connected by springs for broadband energy harvesting

2020 ◽  
Vol 64 (1-4) ◽  
pp. 201-210
Author(s):  
Yoshikazu Tanaka ◽  
Satoru Odake ◽  
Jun Miyake ◽  
Hidemi Mutsuda ◽  
Atanas A. Popov ◽  
...  
Keyword(s):  
Energy Harvesting ◽  
Evaluation Method ◽  
Energy Harvester ◽  
Vibrational Energy ◽  
Functional Materials ◽  
Vibration Energy ◽  
Theoretical Evaluation ◽  
Vibration Energy Harvester ◽  
Polyvinylidene Difluoride ◽  
Simply Supported

Energy harvesting methods that use functional materials have attracted interest because they can take advantage of an abundant but underutilized energy source. Most vibration energy harvester designs operate most effectively around their resonant frequency. However, in practice, the frequency band for ambient vibrational energy is typically broad. The development of technologies for broadband energy harvesting is therefore desirable. The authors previously proposed an energy harvester, called a flexible piezoelectric device (FPED), that consists of a piezoelectric film (polyvinylidene difluoride) and a soft material, such as silicon rubber or polyethylene terephthalate. The authors also proposed a system based on FPEDs for broadband energy harvesting. The system consisted of cantilevered FPEDs, with each FPED connected via a spring. Simply supported FPEDs also have potential for broadband energy harvesting, and here, a theoretical evaluation method is proposed for such a system. Experiments are conducted to validate the derived model.

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