Energy Harvesting Characteristics of Conical Shells

Author(s):  
H. Li ◽  
S. D. Hu ◽  
H. S. Tzou

Piezoelectric energy harvesting has experienced significant growth over the past few years. Various harvesting structures have been proposed to convert ambient vibration energies to electrical energy. However, these harvester’s base structures are mostly beams and some plates. Shells have great potential to harvest more energy. This study aims to evaluate a piezoelectric coupled conical shell based energy harvester system. Piezoelectric patches are laminated on the conical shell surface to convert vibration energy to electric energy. An open-circuit output voltage of the conical energy harvester is derived based on the thin-shell theory and the Donnel-Mushtari-Valsov theory. The open-circuit voltage and its derived energy consists of four components respectively resulting from the meridional and circular membrane strains, as well as the meridional and circular bending strains. Reducing the surface of the harvester to infinite small gives the spatial energy distribution on the shell surface. Then, the distributed modal energy harvesting characteristics of the proposed PVDF/conical shell harvester are evaluated in case studies. The results show that, for each mode with unit modal amplitude, the distribution depends on the mode shape, harvester location, and geometric parameters. The regions with high strain outputs yield higher modal energies. Accordingly, optimal locations for the PVDF harvester can be defined. Also, when modal amplitudes are specified, the overall energy of the conical shell harvester can be calculated.

2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
Yue Zhao ◽  
Yi Qin ◽  
Lei Guo ◽  
Baoping Tang

Vibration-based energy harvesting technology is the most promising method to solve the problems of self-powered wireless sensor nodes, but most of the vibration-based energy harvesters have a rather narrow operation bandwidth and the operation frequency band is not convenient to adjust when the ambient frequency changes. Since the ambient vibration may be broadband and changeable, a novel V-shaped vibration energy harvester based on the conventional piezoelectric bimorph cantilevered structure is proposed, which successfully improves the energy harvesting efficiency and provides a way to adjust the operation frequency band of the energy harvester conveniently. The electromechanical coupling equations are established by using Euler-Bernoulli equation and piezoelectric equation, and then the coupled circuit equation is derived based on the series connected piezoelectric cantilevers and Kirchhoff's laws. With the above equations, the output performances of V-shaped structure under different structural parameters and load resistances are simulated and discussed. Finally, by changing the angle θ between two piezoelectric bimorph beams and the load resistance, various comprehensive experiments are carried out to test the performance of this V-shaped energy harvester under the same excitation. The experimental results show that the V-shaped energy harvester can not only improve the frequency response characteristic and the output performance of the electrical energy, but also conveniently tune the operation bandwidth; thus it has great application potential in actual structure health monitoring under variable working condition.


Author(s):  
Jui-Ta Chien ◽  
Yung-Hsing Fu ◽  
Chao-Ting Chen ◽  
Shun-Chiu Lin ◽  
Yi-Chung Shu ◽  
...  

This paper proposes a broadband rotational energy harvesting setup by using micro piezoelectric energy harvester (PEH). When driven in different rotating speed, the PEH can output relatively high power which exhibits the phenomenon of frequency up-conversion transforming the low frequency of rotation into the high frequency of resonant vibration. It aims to power self-powered devices used in the applications, like smart tires, smart bearings, and health monitoring sensors on rotational machines. Through the excitation of the rotary magnetic repulsion, the cantilever beam presents periodically damped oscillation. Under the rotational excitation, the maximum output voltage and power of PEH with optimal impedance is 28.2 Vpp and 663 μW, respectively. The output performance of the same energy harvester driven in ordinary vibrational based excitation is compared with rotational oscillation under open circuit condition. The maximum output voltage under 2.5g acceleration level of vibration is 27.54 Vpp while the peak output voltage of 36.5 Vpp in rotational excitation (in 265 rpm).


Author(s):  
Zheqi Lin ◽  
Hae Chang Gea ◽  
Shutian Liu

Converting ambient vibration energy into electrical energy using piezoelectric energy harvester has attracted much interest in the past decades. In this paper, topology optimization is applied to design the optimal layout of the piezoelectric energy harvesting devices. The objective function is defined as to maximize the energy harvesting performance over a range of ambient vibration frequencies. Pseudo excitation method (PEM) is applied to analyze structural stationary random responses. Sensitivity analysis is derived by the adjoint method. Numerical examples are presented to demonstrate the validity of the proposed approach.


Author(s):  
Shaofan Qi ◽  
Roger Shuttleworth ◽  
S. Olutunde Oyadiji

Energy harvesting is the process of converting low level ambient energy into usable electrical energy, so that remote electronic instruments can be powered without the need for batteries or other supplies. Piezoelectric material has the ability to convert mechanical energy into electrical energy, and cantilever type harvesters using this material are being intensely investigated. The typical single cantilever energy harvester design has a limited bandwidth, and is restricted in ability for converting environmental vibration occurring over a wide range of frequencies. A multiple cantilever piezoelectric generator that works over a range of frequencies, yet has only one Piezo element, is being investigated. The design and testing of this novel harvester is described.


2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Long Zhang ◽  
Keith A. Williams ◽  
Zhengchao Xie

The power source with the limited life span has motivated the development of the energy harvesters that can scavenge the ambient environment energy and convert it into the electrical energy. With the coupled field characteristics of structure to electricity, piezoelectric energy harvesters are under consideration as a means of converting the mechanical energy to the electrical energy, with the goal of realizing completely self-powered sensor systems. In this paper, two previous models in the literatures for predicting the open-circuit and close-circuit voltages of a piezoelectric cantilever bimorph (PCB) energy harvester are first described, that is, the mechanical equivalent spring mass-damper model and the electrical equivalent circuit model. Then, the development of an enhanced coupled field model for the PCB energy harvester based on another previous model in the literature using a conservation of energy method is presented. Further, the laboratory experiments are carried out to evaluate the enhanced coupled field model and the other two previous models in the literatures. The comparison results show that the enhanced coupled field model can better predict the open-circuit and close-circuit voltages of the PCB energy harvester with a proof mass bonded at the free end of the structure in order to increase the energy-harvesting level of the system.


Author(s):  
S. D. Hu ◽  
H. Li ◽  
H. S. Tzou

Piezoelectric materials can be used as electromechanical conversion mechanisms to transfer ambient vibration into electrical energy to power electronic devices. In this study, an elastic ring laminated with a piezoelectric layer on the inner surface is utilized as the basic structure for energy harvesting. The piezoelectric layer is uniformly segmented into several energy harvesting patches for practical applications. The generated electrical energy resulting from modal voltages is analyzed under the open-circuit condition. Two modal energy generations are evaluated: one is the energy induced by the membrane oscillation and the other is the energy induced by the bending oscillation. For practical design applications, energy generations are evaluated with respect to ring radius, piezoelectric layer thickness, ring thickness and segment size. The maximal energy of all harvester patches on the ring is calculated to determine the optimal patch locations with respect to various ring modes. By summing up energies generated from all harvesters on the ring, the overall energy is also evaluated Based on the normalizations and assumptions of parameters, results indicate that the larger the segment size is, the less the energy can be generated.


Aerospace ◽  
2006 ◽  
Author(s):  
R. M. Tieck ◽  
G. P. Carman ◽  
D. G. Enoch Lee

This paper presents a new approach using frequency rectification to harvest electrical energy from mechanical energy using piezoelectric devices. The rectification approach utilizes a linearly traveling Rectifier to impart vibrational motion to a cantilever piezoelectric bimorph. A conventional cantilever-type energy harvester is tested aside the rectified beam. The Standard beam generated 0.11 W of power, a power density of 15.63 kW/m3, and an energy density of 130.7 J/m3. The Rectified beam generated 580 mW of power, a power density of 871.92 kW/m3, and an energy density of 313.15 J/m3, a factor 2.4 greater than conventional energy harvesting methods. These results confirm the original thesis that a mechanically rectified piezoelectric Energy Harvester would generate larger Energy and Power Densities as well as Specific Powers, compared to conventional technologies.


Author(s):  
M. Carrara ◽  
M. R. Cacan ◽  
J. Toussaint ◽  
M. J. Leamy ◽  
M. Ruzzene ◽  
...  

Enhancement of structure-borne wave energy harvesting is investigated by exploiting metamaterial-based and metamaterial-inspired electroelastic systems. The concepts of wave focusing, funneling, and localization are leveraged to establish novel Metamaterial–Energy Harvester (MEH) configurations. The MEH system transforms the incoming structure-borne wave energy into electrical energy by coupling the metamaterial and electroelastic domains. The energy harvesting component of the work employs piezoelectric transduction due to the high power density and ease of application offered by piezoelectric materials. Therefore, in all MEH configurations studied in this work, the metamaterial system is combined with piezoelectric energy harvesting for enhanced electricity generation from waves propagating in elastic structures. Experiments are conducted to validate the dramatic performance enhancement in MEH systems as compared to using the same volume of piezoelectric patch in the absence of the metamaterial component. It is shown that MEH systems can be used for both broadband and tuned wave energy harvesting. Examples include (1) wave guiding using an acoustic funnel, (2) wave focusing using a metamaterial-inspired elliptical acoustic mirror (both for broadband energy harvesting), and (3) energy localization using an imperfection in a 2-D lattice structure (for tuned energy harvesting).


Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2876
Author(s):  
Hailu Yang ◽  
Ya Wei ◽  
Weidong Zhang ◽  
Yibo Ai ◽  
Zhoujing Ye ◽  
...  

Road power generation technology is of significance for constructing smart roads. With a high electromechanical conversion rate and high bearing capacity, the stack piezoelectric transducer is one of the most used structures in road energy harvesting to convert mechanical energy into electrical energy. To further improve the energy generation efficiency of this type of piezoelectric energy harvester (PEH), this study theoretically and experimentally investigated the influences of connection mode, number of stack layers, ratio of height to cross-sectional area and number of units on the power generation performance. Two types of PEHs were designed and verified using a laboratory accelerated pavement testing system. The findings of this study can guide the structural optimization of PEHs to meet different purposes of sensing or energy harvesting.


2021 ◽  
Vol 12 (07) ◽  
pp. 318-329
Author(s):  
Indrajit Chandra Das ◽  
Md. Arafat Rahman ◽  
Sanjoy Dam

Energy harvesting is defined as a process of acquiring energy surrounding a system and converting it into electrical energy for usage. Piezoelectric energy harvesting is a very important concept in energy harvesting in microelectronics. In this report, an analysis of the cantilever type piezoelectric energy harvester is conducted using the finite element method (FEM) based software COMSOL Multiphysics. A unimorph type cantilever beam of the silicon substrate, structural steel as proof mass and support, and PZT-5A material as piezoelectric constitute the physical system.


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