Coupling loss factor of linear vibration energy harvesting systems in a framework of statistical energy analysis

2016 ◽  
Vol 362 ◽  
pp. 125-141 ◽  
Author(s):  
Xu Wang
Keyword(s):  
Energy Harvesting ◽  
Loss Factor ◽  
Energy Analysis ◽  
Vibration Energy ◽  
Statistical Energy Analysis ◽  
Coupling Loss ◽  
Linear Vibration ◽  
Vibration Energy Harvesting ◽  
Harvesting Systems ◽  
Coupling Loss Factor

Prediction of Transient Vibration Envelopes Using Statistical Energy Analysis Techniques

1990 ◽  
Vol 112 (1) ◽  
pp. 127-137 ◽  
Author(s):  
M. L. Lai ◽  
A. Soom
Keyword(s):  
Loss Factor ◽  
Energy Analysis ◽  
A Priori ◽  
Coupled Systems ◽  
Time Varying ◽  
Statistical Energy Analysis ◽  
Coupling Loss ◽  
Transient Vibration ◽  
Coupled Plates ◽  
Coupling Loss Factor

The prediction, by the statistical energy analysis (SEA) method, of transient vibration envelopes for coupled systems is investigated. The relation between the time-varying energy transferred between two coupled subsystems and time-varying energies of the subsystems is studied numerically and experimentally. These studies indicate that time-varying energy transmitted between two subsystems is related to the subsystem energies by an apparent time-varying coupling loss factor. It is shown that the apparent coupling loss factor approaches the asymptotic (or steady-state) coupling loss factor as response energies and transferred energies are integrated over progressively larger times. Both the apparent time-varying coupling loss factor and the asymptotic coupling loss factor, determined experimentally, are used in energy balance equations to predict the time-varying vibration envelopes of a system of two point-coupled plates and the results are compared. Although overall response predictions are similar, considerable differences are noted in individual frequency bands. However, no general method for a priori determination of the apparent time-varying coupling loss factor is suggested.

Application of Statistical Energy Analysis for Damage Detection in Spacecraft Structures

2005 ◽  
Vol 293-294 ◽  
pp. 525-532 ◽  
Author(s):  
J. López-Díez ◽  
M. Torrealba ◽  
A. Güemes ◽  
C. Cuerno-Rejado
Keyword(s):  
Damage Detection ◽  
Loss Factor ◽  
Energy Analysis ◽  
Stiffened Panel ◽  
Statistical Energy Analysis ◽  
Coupling Loss ◽  
System Characteristics ◽  
Coupling Loss Factor

This paper analyses the applicability of the Statistical Energy Analysis (SEA) for detecting incipient damages in a typical spacecraft structure, as a stiffened panel. The damage on attachment element is investigated by analyzing its influence on the system characteristics. Because of incipient damage affects mainly on highest modes, rather than on lowest, the coupling loss factor between sub-elements can be used to detect and localize the damage.

An experimentally validated analytical model for the coupled electromechanical dynamics of linear vibration energy harvesting systems

2016 ◽  
Vol 28 (1) ◽  
pp. 3-22 ◽  
Author(s):  
Brennan E Yamamoto ◽  
A Zachary Trimble
Keyword(s):  
Energy Harvesting ◽  
Transfer Function ◽  
Analytical Model ◽  
Damping Ratio ◽  
Vibration Energy ◽  
Experimental Setup ◽  
Linear Vibration ◽  
Vibration Energy Harvesting ◽  
Electromechanical Model ◽  
Harvesting Systems

Recent technological advancements in the efficiency of microprocessors, sensors, and other digital logic systems have increased research effort in vibration energy harvesting, where trace amounts of energy are scavenged from the ambient environment to provide power. Due to the complexity and nonlinearity of most vibration energy harvesting systems, existing research has relied primarily on numerical and finite element methods for harvester design and validation. Although these methods are useful, a vetted analytical model provides intuitive understanding of the governing dynamics and is useful for obtaining rough calculations when designing vibration energy harvesting systems. In this article, an analytical framework for linear electromechanical transducer modeling is developed into the coupled electromechanical model; a transfer function characterizing the dynamics of second-order VEH systems, which includes inputs for mechanical and electrical domain lumped parameters as complex impedances. The coupled electromechanical model transfer function is validated against frequency sweep data from a linear vibration energy harvesting experimental setup. The experimental setup demonstrated good correlation with the coupled electromechanical model, with not more than 0.9% error in natural frequency overall, 6% error in damping ratio for purely resistive loads, and 11% for reactive loads.

Statistical energy analysis parameter estimation for different structural junctions of rectangular plates

2016 ◽  
Vol 230 (15) ◽  
pp. 2603-2610 ◽  
Author(s):  
Maruti B Mandale ◽  
P Bangaru Babu ◽  
SM Sawant
Keyword(s):  
Loss Factor ◽  
Energy Analysis ◽  
Rectangular Plates ◽  
Statistical Energy Analysis ◽  
Coupling Loss ◽  
Drawing Board ◽  
Board Stage ◽  
Good Agreement ◽  
Coupling Loss Factor ◽  
Loss Factors

In industries, the use of appropriate junctions between components is of paramount interest. Coupling loss factor is one of the important parameters in statistical energy analysis for vibroacoustic analysis of complicated structures in drawing board stage. The values of coupling loss factor were calculated and compared for different junctions. The screwed and bolted junctions were examined for thin rectangular plates of same size. The energy level difference method was used to find coupling loss factors because of its simplicity. These experimentally found coupling loss factors were later compared with analytical solutions. It is noticed that the analytical results are in good agreement with experimental results. It is also observed that coupling loss factor for bolted junction are relatively high than that for screwed junction.

scholarly journals A Theory for Energy-Optimized Operation of Self-Adaptive Vibration Energy Harvesting Systems with Passive Frequency Adjustment

Micromachines ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 44 ◽  
Author(s):  
Mario Mösch ◽  
Gerhard Fischerauer
Keyword(s):  
Energy Harvesting ◽  
Resonance Frequency ◽  
Optimal Operation ◽  
Energy Output ◽  
Vibration Energy ◽  
Vibration Energy Harvesting ◽  
Vibration Energy Harvester ◽  
Frequency Adjustment ◽  
Harvesting Systems ◽  
Self Adaptive

Self-adaptive vibration energy harvesting systems vary their resonance frequency automatically to better exploit changing environmental conditions. The energy required for the adjustment is taken from the energy storage of the harvester module. The energy gained by an adjustment step has to exceed the energy expended on it to justify the adjustment. A smart self-adaptive system takes this into account and operates in a manner that maximizes the energy output. This paper presents a theory for the optimal operation of a vibration energy harvester with a passive resonance-frequency adjustment mechanism (one that only requires energy for the adjustment steps proper, but not during the hold phases between the steps). Several vibration scenarios are considered to derive a general guideline. It is shown that there exist conditions under which a narrowing of the adjustment bandwidth improves the system characteristics. The theory is applied to a self-adaptive energy harvesting system based on electromagnetic transduction with narrowband resonators. It is demonstrated that the novel optimum mode of operation increases the energy output by a factor of 3.6.

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