scholarly journals The Effect of the Parameters of a Vibration-Based Impact Mode Piezoelectric Power Generator

2015 ◽  
Vol 2015 ◽  
pp. 1-9
Author(s):  
Amat A. Basari ◽  
S. Awaji ◽  
S. Sakamoto ◽  
S. Hashimoto ◽  
B. Homma ◽  
...  
Keyword(s):  
Output Power ◽  
Impact Velocity ◽  
High Velocity ◽  
Output Voltage ◽  
Quadratic Function ◽  
Frequency Bandwidth ◽  
Power Generator ◽  
Piezoelectric Device ◽  
The Impact ◽  
Impact Mode

This study reports the effects of the parameters of a vibration-based impact mode piezoelectric power generator. First, an evaluation of the effects of the impact parameters, the mass, and the impact velocity is presented. It is found that the output voltage of the piezoelectric device in impact mode is directly proportional to the velocity, whereas the output power is equal to a quadratic function of the same variable. For the same impact momentum, the effect of the velocity in generating a higher peak output is dominant compared with the mass. Second, the vibration-based impact mode piezoelectric power generator is discussed. The experimental results show that a wider operating frequency bandwidth of the output power can be achieved with the preloading configuration. However, regarding magnitude, due to the high velocity of impact, the configuration with a gap between the tip and the piezoelectric device produces a higher output.

Mechanical Damage to Pinto Bean Seeds as Affected by Moisture Content, Impact Velocity and Seed Orientation

2012 ◽  
Vol 7 (6) ◽  
Author(s):  
Feizollah Shahbazi ◽  
Mohamad Analooei ◽  
Ali Saffar
Keyword(s):  
Moisture Content ◽  
Impact Velocity ◽  
Impact Damage ◽  
Quadratic Function ◽  
Physical Damage ◽  
Seed Moisture Content ◽  
Mean Values ◽  
Pinto Bean ◽  
The Mean ◽  
The Impact

The objective of this experiment was evaluate of the impact damage to pinto bean seeds where seed moisture content (9.25, 12.51, 15.01, 17.52, 20.01% wet basis), impact velocity (5.5, 8, 10, 12.5 and 15m/s) and seed orientation (end and side) were independent variables. The study was conducted under laboratory conditions, using an impact damage assessment device. The results showed that impact velocity, moisture content and seed orientation significantly influenced the physical damages of pinto beans at 1% level. Increasing the impact velocity from 5.5 to 15m/s caused an increase in the mean values of damage from 0.39 to 37.30%. With increase the moisture content from 9.25 to 17.52%, the mean values of percentage of damaged beans decreased significantly from 41.24 to 4.27%. However, by a higher increase in the moisture from 17.52 to 20.01%, the mean values of physically damaged beans showed a nonsignificant increasing trend. There was an optimum moisture level of 17.52% at which seed damage was minimized. The relationship between the percent of physical damage with impact velocity and beans moisture content was expressed mathematically. It was found that the percentage damage to seeds was a quadratic function of moisture content and impact velocity. Impact to the end of the seeds (18.62%) produced the higher damage than side orientation (13.12%).

Ballistic performance and damage simulation of fiber metal laminates under high-velocity oblique impact

2020 ◽  
Vol 29 (7) ◽  
pp. 1011-1034 ◽  
Author(s):  
Chao Zhang ◽  
Qian Zhu ◽  
Jose L Curiel-Sosa ◽  
Tinh Quoc Bui
Keyword(s):  
Impact Velocity ◽  
High Velocity ◽  
Damage Mechanics ◽  
Failure Modes ◽  
Element Model ◽  
Oblique Impact ◽  
Ballistic Performance ◽  
Fiber Metal Laminates ◽  
Fiber Metal ◽  
The Impact

Fiber metal laminates have been successfully applied in military aircrafts, armor vehicles and other modern engineering industries as protective structures due to their outstanding impact resistant properties. Prediction of the ballistic performance and investigation on the damage mechanism of the fiber metal laminates under general oblique impact conditions still remain a very challenging issue. In this study, a nonlinear dynamic finite element model in terms of continuum damage mechanics including intra- and inter-layer failure modes is presented. The accuracy of this model is validated with available experimental data. The damage and ballistic performance of two different structural fiber metal laminates subjected to high-velocity oblique impact by rigid hemispherical nose projectile with angles of 0°, 30°, 45° and 60° are studied. The numerical results show that the projectile deflects when the oblique impact occurs and the deflection angle decreases with increasing the impact velocity. The residual velocity of the projectile and the energy absorption of the target are related to the initial impact velocity and impact angle of the projectile. The proposed simulation approach offers a new proper reference for numerical investigations of common oblique impact problems in other fiber metal laminates.

Damage Analysis of Thermal Barrier Coatings Subjected to a High-Velocity Impingement of a Solid Sphere

2019 ◽  
Vol 827 ◽  
pp. 349-354
Author(s):  
Kiyohiro Ito ◽  
Fei Gao ◽  
Masayuki Arai
Keyword(s):  
Gas Turbine ◽  
Impact Velocity ◽  
Thermal Barrier Coatings ◽  
High Velocity ◽  
Turbine Blades ◽  
Interfacial Crack ◽  
Thermal Barrier ◽  
Barrier Coatings ◽  
Wide Range ◽  
The Impact

A delamination of thermal barrier coatings (TBC) applied to turbine blades in gas turbine could be caused by a high-velocity impingement of various foreign objects. It is important to accurately predict the size of interfacial crack for safety operation of gas turbine. In this study, in order to establish a practical equation for prediction of the length of interfacial crack, a high velocity impingement test and a finite element analysis (FEA) based on a cohesive model were conducted. As the result, the length of interfacial crack is linearly increased with the impact velocity. In addition, it was confirmed that it was accurately estimated by the FEA. The equation for prediction of the length of interfacial crack was formulated based on these results and the energy conservation before and after impingement. Finally, the applicability of the equation was demonstrated in a wide range of impact velocity through a comparison with the experimental results.

Boiling during high-velocity impact of water droplets on a hot stainless steel surface

2006 ◽  
Vol 462 (2074) ◽  
pp. 3115-3131 ◽  
Author(s):  
Navid Z Mehdizadeh ◽  
Sanjeev Chandra
Keyword(s):  
Stainless Steel ◽  
Substrate Temperature ◽  
Impact Velocity ◽  
High Velocity ◽  
Steel Surface ◽  
Stainless Steel Surface ◽  
High Velocity Impact ◽  
Water Droplets ◽  
Velocity Impact ◽  
The Impact

High-velocity impact of water droplets (0.55 mm diameter) on a heated stainless steel surface was photographed. To achieve high impact velocities, the test surface was mounted on the rim of a rotating flywheel, giving linear velocities of up to 50 m s −1 . Two cartridge heaters were inserted in the substrate and used to vary substrate temperature. A charge coupled device (CCD) video camera was used to photograph droplets impinging on the substrate. To photograph different stages of droplet impact, the ejection of a single droplet was synchronized with the position of the rotating flywheel and triggering of the camera. Substrate temperature was varied from 100 to 240 °C and the impact velocity from 10 to 30 m s −1 . High-resolution photographs were taken of vapour bubbles nucleating sites inside the thin liquid films produced by spreading droplets. An analytical expression was derived for the amount of superheat required for vapour bubble nucleation as a function of the impact velocity. For a given surface roughness, the amount of superheat needed decreased with impact velocity, which agreed with experimental results. For a fixed impact velocity, the maximum extent of droplet spread increased with substrate temperature.

High Velocity Compaction : Overview of Materials, Applications and Potential

2007 ◽  
Vol 534-536 ◽  
pp. 293-296 ◽  
Author(s):  
Florence Dore ◽  
Ludovic Lazzarotto ◽  
Stephane Bourdin
Keyword(s):  
Impact Velocity ◽  
High Velocity ◽  
New Technology ◽  
Machining Process ◽  
Powder Materials ◽  
Component Shape ◽  
High Velocity Compaction ◽  
Set Up ◽  
The Impact ◽  
Sintered Materials

Since 2000, CETIM has been equipped with a High Velocity Press that can deliver up to 5 shots per second with each blow accurately set up (up to 20000J) thanks to the impact velocity regulation (up to 11m.s-1). Through different projects, CETIM and its scientific and industrial partners have evaluated the potential of this new technology in terms of materials and component shape. Various kinds of powder materials were studied: metals, ceramics and polymers. The HVC process was used with success to manufacture gears, large parts and multilevel components. More than, the green machining process that enables shapes to be produced that would otherwise be impossible to compact is improved by the high density of HVC parts and it is also an opportunity to produce components with very hard sintered materials.

scholarly journals Rancang Bangun Alternator Mobil Menggunakan Magnet Permanen

2021 ◽  
Vol 19 (2) ◽  
pp. 163
Author(s):  
Andareas Pangkung ◽  
A. M. Shiddiq Yunus ◽  
Mustari Nur Mulyadi ◽  
Padidi Alfrianto Illa
Keyword(s):  
Permanent Magnet ◽  
Output Power ◽  
Output Voltage ◽  
Permanent Magnets ◽  
Input Power ◽  
Electric Power System ◽  
Electrical System ◽  
Power Generator ◽  
Electric Component ◽  
Development Methods

The electric power system is one of the sources of electricity found in the vehicle which functions as a starter and electric component of the vehicle. The battery (battery) is a source of electricity to meet the electrical system in the car, but the battery is only a place to store electric charge. Therefore, there is an alternator as a power generator to charge the battery. The alternator on a car uses artificial magnets in its rotor which still require excitation. Therefore, it encourages the author to analyze the comparison of alternators using permanent magnets and artificial magnets. The problem that arises is how to compare rotation, voltage, and output power on the alternator using permanent magnets and artificial magnets. The purpose of this study was to determine the ratio of the output power generated by the alternator using permanent magnets and artificial magnets. Research and Development Methods are research methods used to produce certain products, and test the effectiveness of these products. Based on the results of the tests carried out, it was found that at the same rotation an alternator with a permanent magnet generates a greater output power than the artificial magnet. However, at the same rotation the motor requires more input power to rotate the alternator when using permanent magnets. When the alternator output voltage is the same, the rotation of the alternator using the permanent magnet is lower.

Modeling an Impact Vibration Harvester With Triboelectric Transduction

2017 ◽  
Author(s):  
Alwathiqbellah Ibrahim ◽  
Abdallah Ramini ◽  
Shahrzad Towfighian
Keyword(s):  
Charge Density ◽  
Surface Charge ◽  
Surface Charge Density ◽  
Output Voltage ◽  
Energy Harvester ◽  
Vibrational Energy ◽  
Vibrational Amplitude ◽  
Pdms Layer ◽  
Frequency Bandwidth ◽  
The Impact

We demonstrate numerically an efficient vibrational energy harvester based on a triboelectric mechanism. The energy harvester consists of a clamped-clamped beam with center mass to enable the impact between the triboelectric layers subjected to external vibrations. The lower electrode is aluminum covered with a polydimethylsiloxane (PDMS) layer and the top electrode is an aluminum foil. Upon contact, electric charges are generated and alternative current flows between the upper and lower electrodes. We report the frequency bandwidth gets wider with a hardening behavior introduced by the impact nonlinearity in the structure. We then investigate the effect of the surface charge density on the output voltage, current, and power. The output voltage and power are as large as 1.73 V, 3 μW, respectively with 0.4 g vibrational amplitude and 30 μC/m2 surface charge density. The frequency bandwidth ranged between 5–18 Hz.

Effect of Relative Density on the Dynamic Impact Behaviors of Closed-Cell Foam

2016 ◽  
Author(s):  
Shilong Wang ◽  
Yuanyuan Ding ◽  
Changfeng Wang ◽  
Zhijun Zheng ◽  
Jilin Yu
Keyword(s):  
Shock Wave ◽  
Relative Density ◽  
Impact Velocity ◽  
High Velocity ◽  
Wave Speed ◽  
Material Parameter ◽  
Dynamic Strain ◽  
Closed Cell ◽  
The Impact ◽  
Cell Foam

Dynamic behaviors of closed-cell foam are investigated with cell-based finite element models based on the 3D Voronoi technique. The typical deformation feature of cellular structures under high-velocity impact is layer by layer collapse, like a shock wave propagating in the specimen. The one-dimensional velocity distribution of the structure is calculated to characterize the propagation of shock front and thus the shock wave speed is determined quantitatively. It is found that the shock wave speed has intense dependence on the impact velocity for a specific relative density. The difference between the shock wave speed and the impact velocity is asymptotic to a constant as the impact velocity increases. This constant can be therefore regarded as a dynamic material parameter. The influence of relative density on this dynamic material parameter is investigated. The results show that the shock wave speed at a specific impact velocity increases with the increase of the relative density of cellular structure in a certain extent. An expression of the shock wave speed with respect to the impact velocity and relative density is obtained. The dynamic strain hardening parameter is lower than that in the quasi-static one, which indicates different mechanisms of the deformation under high-velocity and quasi-static loadings.

scholarly journals Analytical Modeling of a Doubly Clamped Flexible Piezoelectric Energy Harvester with Axial Excitation and Its Experimental Characterization

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3861
Author(s):  
Jie Mei ◽  
Qiong Fan ◽  
Lijie Li ◽  
Dingfang Chen ◽  
Lin Xu ◽  
...  
Keyword(s):  
Output Power ◽  
Power Output ◽  
Output Voltage ◽  
Energy Harvester ◽  
Load Resistance ◽  
Engineering Practice ◽  
Maximum Output ◽  
Widespread Application ◽  
Piezoelectric Energy ◽  
Axial Excitation

With the rapid development of wearable electronics, novel power solutions are required to adapt to flexible surfaces for widespread applications, thus flexible energy harvesters have been extensively studied for their flexibility and stretchability. However, poor power output and insufficient sensitivity to environmental changes limit its widespread application in engineering practice. A doubly clamped flexible piezoelectric energy harvester (FPEH) with axial excitation is therefore proposed for higher power output in a low-frequency vibration environment. Combining the Euler–Bernoulli beam theory and the D’Alembert principle, the differential dynamic equation of the doubly clamped energy harvester is derived, in which the excitation mode of axial load with pre-deformation is considered. A numerical solution of voltage amplitude and average power is obtained using the Rayleigh–Ritz method. Output power of 22.5 μW at 27.1 Hz, with the optimal load resistance being 1 MΩ, is determined by the frequency sweeping analysis. In order to power electronic devices, the converted alternating electric energy should be rectified into direct current energy. By connecting to the MDA2500 standard rectified electric bridge, a rectified DC output voltage across the 1 MΩ load resistor is characterized to be 2.39 V. For further validation of the mechanical-electrical dynamical model of the doubly clamped flexible piezoelectric energy harvester, its output performances, including both its frequency response and resistance load matching performances, are experimentally characterized. From the experimental results, the maximum output power is 1.38 μW, with a load resistance of 5.7 MΩ at 27 Hz, and the rectified DC output voltage reaches 1.84 V, which shows coincidence with simulation results and is proved to be sufficient for powering LED electronics.

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