Convert Vibration Energy Research Articles

Variable stiffness triboelectric nano-generator to harvest high-speed railway bridge’s vibration energy

The integration of vibrating structure and novel energy harvesters is highly desirable for the conversion of vibration energy to electricity. In this paper, a variable stiffness triboelectric nano-generator (VSTENG) composed of a variable stiffness part (VSP) and multiple sets of triboelectric nano-generators (TENGs) is proposed to harvest vibration energy of high-speed railway bridge for meeting the electrical energy requirements of sensor nodes. The working principle of VSTENG is introduced, and the theoretical models of VSP’s force-displacement and TENG’s electrical energy output are derived. The numerical model for the VSTENG is presented and a detailed finite element model for the train-track-bridge system is also established. Then by simulating the running train on the bridge, the vibration responses and corresponding frequency spectrum of the track-bridge structure are analyzed, and the effect of VSTENG’s design parameters is discussed. The results show that the developed energy harvester can enlarge the displacement response and vibrate in a wide-frequency domain inducing partial nonlinearity. Moreover, the shake table tests are conducted, and the effect of design parameters and load resistance are analyzed. The test has shown that the device gets the maximum value of electrical energy output while adopting the track plate response as an input. As the load resistance increases, the electrical energy output would be further increased and then decreases sharply. The TENGs can effectively utilize the amplified displacement and wide-range vibration caused by the VSP and promotes the energy harvesting capacity.

System-level modeling and design method of an array of piezoelectric energy harvesters under typical ambient vibration

Vibration-based piezoelectric energy harvesting has received significant attention recently due to its ability to convert vibration energy from the surrounding environment into electric energy to power wireless sensors. In this work, two typical types of vibration sources, that is, engine-induced floor vibration and train-induced bridge vibration, are considered. The array of piezoelectric energy harvesters (PEHs) is adopted to harvest the energy of vibration with different frequencies. The aim of this work is to give a stable system-level modeling method and present a method to select operating point for designing energy harvesters connected with nonlinear energy harvesting circuits under complex excitations. The system-level modeling method is based on Krylov’s subspace model order reduction algorithm. With the help of this method, the harvester can be modeled using conventional finite element software and co-simulated with nonlinear circuits at a system-level. The proposed method is validated using equivalent circuit method, equivalent impedance method and experiment results, and then employed to investigate the performances of harvesters under typical real vibrations. Finally, design suggestions for PEHs under different types of vibration sources are presented.

Analysis of the vibro-acoustic behaviours of underwater reinforced rectangular plates

In this paper, the vibration and sound radiation of underwater stiffened plates with arbitrary boundary condition have been studied. The vibration of the structure is described by an improved Fourier series, the water-load acts on the structure is solved by Rayleigh integral, and the dynamic response is solved by an energy method. The results show that the increase of plate thickness and boundary constraint can enhance the vibration and sound transformation ability of underwater rectangular plate, and the mechanism is that the increase of vibration mode frequency increases the radiation efficiency of the dominant acoustic radiation mode. By analyzing the effect of stiffening mode and quantity on acoustic radiation, it can be seen that for the plate (1,1) mode, the longitudinal stiffening mode has the lowest vibration energy conversion rate, and the main mechanism is that the dominant acoustic radiation mode has the lowest radiation efficiency, while the transverse stiffening mode has the highest radiation efficiency. In addition, when the reinforcement is distributed, the natural frequency and the radiation efficiency of the corresponding dominant acoustic radiation modes of the stiffeners are reduced, the vibration- acoustic conversion of the plate showed a decreasing trend.

Effect of magnetic field on output performance of magnetic liquid vibration energy harvester

PurposeThe purpose of this study is to develop a friction-type energy-harvesting device based on magnetic liquids (MLs). This MLs energy-harvesting device combines MLs with a triboelectric nanogenerator (TENG), reducing the friction thermal effect to improve the conversion efficiency and working frequency band.Design/methodology/approachFirst, the motion equation of the MLs is calculated using the Bernoulli and fluid continuity equations. Second, the sloshing process of an ML in a container is simulated using the finite element simulation method, and the magnetic field distribution of the permanent magnet in the MLs is calculated. Then, the output characteristic of the ML-TENG is deduced theoretically, and the influencing factors of the output voltage are analyzed. Finally, the output voltage of the MLs energy-harvesting device was tested experimentally, and the influence of the magnetic field on the output voltage was tested.FindingsThis study proposes a vibration energy harvesting device based on MLs. The output voltage of the device was obtained through simulation and experimental tests, and the effect of the magnetic field on the output voltage was obtained.Originality/valueThis study provides a method to convert vibration energy into electrical energy using the magnetic response and fluid characteristics of MLs, and the availability of the device is verified by simulation and experiment. This energy-harvesting device exhibits less loss and a more sensitive response.

Validation and Evaluation of a Behavioral Circuit Model of an Enhanced Electrostatic MEMS Converter

In this current study, the validation and evaluation of a behavioral circuit model of electrostatic MEMS converters are presented. The main objective of such a model is to accurately find the converter behavior through the proper choice of its circuit elements. In this regard, the model enables the implementation of the electrostatic MEMS converter using commercially available off-shelf circuit elements. Thus, the overall vibration energy harvesting system can be implemented and tested without the need for fabricating the converter. As a result, the converter performance can be verified and evaluated before its fabrication which saves the expenses of fabricating trailed prototypes. To test the model, we apply it to an enhanced converter in which the conventional electrostatic MEMS converter is modified by depositing the tantalum pentoxide, Ta2O5, a high dielectric constant material, on its fingers’ sidewalls. Such a deposition technique causes an appreciable increase in the overall converter capacitance and, in turn, the output power, which is boosted from the range of µw to the range of mW. Next, the converter behavioral circuit model, which is based on representing its capacitances variations with respect to the input displacement, x caused by the vibration signal, C–x curve, is built up. The model is qualitatively validated and quantitatively evaluated. The enhanced converter performance is investigated through the interaction of its model with the power conditioning circuit. From the simulation results, it is revealed that the converter behavioral circuit model accurately accomplishes the vibration energy conversion operation. As a result, the specification of the required controlling pulses for the converter operation is accurately determined. Finally, the model accuracy is validated by calibrating its performance with a traditionally simulated and fabricated electrostatic MEMS converter.

Study on Vibration Energy Conversion Efficiency of the Drill String Absorption & Hydraulic Supercharging Device

Study on Vibration Energy Conversion Efficiency of the Drill String Absorption & Hydraulic Supercharging Device

Self-Powered Downhole Drilling Tools Vibration Sensor Based on Triboelectric Nanogenerator

The vibration state of the drilling tool is particularly important for its working condition monitoring. Here, a self-powered downhole drilling tools vibration sensor (hereafter referred to as V-TENG) based on triboelectric nanogenerator (TENG) is proposed. The V-TENG, which is designed as the single electrode and independent layer TENG, can synchronously realize the measurement of drilling tools vibration frequency and amplitude. Test results show that the frequency measuring range is 0 to 13 Hz, with an error of no more than 5%, and the amplitude measuring range is 0 to 130 mm, with a resolution of 10 mm and a maximum deviation of 5 mm. In addition, the possibility of the sensor converting vibration energy into electrical energy and providing power for other measuring instruments was explored, the test results show that the maximum power of the frequency measuring module is <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$88.92\times 10$ </tex-math></inline-formula> <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−8</sup> W with <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$10^{8} {\boldsymbol \Omega } $ </tex-math></inline-formula> resistance in series, while the amplitude measurement is <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$28.62\times 10$ </tex-math></inline-formula> <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−9</sup> W with <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$10^{9} {\boldsymbol \Omega }$ </tex-math></inline-formula> resistance in series. Compared with traditional downhole vibration sensors, the V-TENG can synchronously measure the drill string vibration frequency and amplitude in a self-powered model, which is more suitable for downhole conditions.

Analisis Pengaruh Frekuensi Osilasi Pegas Terhadap Tegangan Listrik yang Dihasilkan Alat Peredam Kejut Regeneratif Elektromagnetik Skala Laboratorium

Abstract— EMRSA is a tool that can generate electrical energy by utilizing vibration energy that is wasted in a vehicle. Vibration energy includes energy that is wasted on vehicles and is still very rarely used. Therefore, in this study, an experiment was carried out to convert vibration energy into electrical energy. The purpose of this study was to determine the effect of the frequency of spring oscillations on the electric voltage produced by a laboratory-scale regenerative shock absorber. The research was carried out by providing variations in the load on the spring so that a different frequency was obtained in each experiment. The results of the experiment show that the frequency of the spring oscillation is directly proportional to the result of the electric voltage generated. The higher the frequency given, the greater the resultant voltage generated. From the experiments that have been carried out, the results of the electrical voltage of 0.537 volts are obtained at a frequency of 3.37 Hz with a number of copper coils of 500 turns and a copper diameter of 0.1 mm.

Development and Performance Analysis of a New Self-Powered Magnetorheological Damper with Energy-Harvesting Capability

Magnetorheological (MR) dampers, used as intelligent semi-active vibration control devices to achieve low energy consumption, fast response, controllability, and other capabilities are generally installed with a variety of sensors on their exterior to ensure that the damping force can be accurately controlled. However, external sensors are often affected by external complications that reduce the reliability of the damper, and the cost of powering the damper coils in remote locations where power is not available can be significantly increased. Based on these problems, a new self-powered MR damper scheme is proposed. The proposed MR damper has both energy-harvesting capabilities and damping controllability, and greatly improves the stability and application range of the device by converting vibration energy into electrical energy to supply the excitation coil. The MR damper can drive the piston rod in a linear reciprocating motion by external excitation, which converts mechanical energy into electrical energy via a DC brushless three-phase generator after conversion by a double-linkage mechanism. At the same time, the electrical energy generated by the generator is passed into the excitation coil to change the output damping force of the damper. Meanwhile, the damping performance and energy-harvesting efficiency of the new self-powered MR damper is experimentally tested. Experimental results show the damping force of the device reaches 1040 N when the applied current is 0.6 A. The proposed self-powered MR damper has an instantaneous voltage amplitude of 1.782 V and a peak phase power of 4.428 W when the input excitation amplitude is 12.5 mm and the frequency is 3 Hz.

A Novel Non-Intrusive Vibration Energy Harvesting Method for Air Conditioning Compressor Unit

The purpose of harvesting vibration energy is to obtain clean and sustainable energy by converting vibration energy from ambient sources into a voltage output. In this work, a piezoelectric sensor, PZT-5H is attached to a 3D printed and custom-made mounting to be placed at an air conditioning condenser unit, to harvest vibration energy. The configuration of the harvester is non-intrusive, in which the harvester did not intrude into compressor unit operation. Temperature (20 °C, 22 °C, and 24 °C) and air volume flow rates (3 levels of air volume flow rate at 245 L/second, 274 L/second, and 297 L/second) were taken into consideration in this investigation. An accelerometer was first used to investigate the optimum vibration frequency in Hertz, and six locations were identified. Next, the piezoelectric sensor was mounted at these six locations, and the output root-mean-square (RMS) voltage from the piezoelectric sensor was obtained. The analysis of variance (ANOVA) indicated that temperature and air volume flow rates factors were significant. It was found that the location identified with the highest amount of vibration at 830.2 Hz from accelerometer measurement, was also the highest amount of RMS voltage, at 510.82 mV, harvested by the piezoelectric, from the temperature of 20 °C and air volume flow rates at high level (air flow volume flow rate at 297 L/second). From this work, it is feasible to utilize this novel method of harvesting waste vibration energy from the air conditioning compressor unit.

Numerical and Experimental Investigation of a Semi-Active Vibration Control System by Means of Vibration Energy Conversion

A vibration control concept based on vibration energy conversion and storage with respect to a serial-stiffness-switch system (4S) has previously been proposed. Here, we first present a rotational electromagnetic serial-stiffness-switch system as a novel practical vibration control system for experimental validation of the concept and, furthermore, an improved control strategy for higher vibration suppression performance is also proposed. The system consists of two spring-switch elements in series, where a parallel switch can block a spring. As an alternating mechanical switch, the experimental system uses two electromagnets with a shared armature. By connecting the armature to the rotating load or the base, the electromagnets decide which of the two spiral springs is blocked, while the other is active. A switching law based on the rotation velocity of the payload is used. Modelling and building of the experimental system were carried out. The corresponding experiment and simulation were executed and they matched well. These results prove that our serial-stiffness-switch system is capable of converting vibration energy and realizing vibration reduction under a forced harmonic disturbance. The effects of disturbance frequency, disturbance amplitude and sampling frequency on the system performance are shown as well. A position feedback control-based switching law is further put forward and experimentally verified to improve the repositioning accuracy of the disturbed system.

Design of a Bézier-Profile Plate for Closely Spaced Multimodal Vibration Energy Harvesting

A cubic Bézier-profile plate for multimodal vibration energy harvesting was developed. The design of the plate was based on an optimization procedure in which the profile of the plate was optimized via the parameters of a cubic Bézier curve to meet the requirements. The multimodal energy harvesting of the plate exploited its first bending mode and its first twisting mode. The conversion of vibration energy into electrical energy was by electromagnetic induction with a magnet attached to a corner of the plate. These two closely spaced vibration modes achieved the multi-modal energy harvesting of the device. Prototypes of the device were manufactured using a numerical-control machining process. The experimental results were in good agreement with the design specifications. With the same base lengths, height, and thickness, the maximum von Mises stress of the proposed plate was much lower due to its bell-shaped profile. The cubic Bézier curve chosen for the plate profile was effective for design of the closely-spaced multimodal vibration energy harvester. With the flexibility of its controllable parametric curve, a high design freedom of the energy harvester with specified frequency ratios could be achieved.

Experimental and Numerical Characterization of a Gravitational Electromagnetic Energy Harvester

In this paper, the dynamic experimental identification of an inductive energy harvester for the conversion of vibration energy into electric power is presented. Recent advances and requirements in structural monitoring and vehicle diagnostic allow defining Autonomous Internet of Things (AIoT) systems that combine wireless sensor nodes with energy harvester devices properly designed considering the specific duty cycle. The proposed generator was based on an asymmetrical magnetic suspension and was addressed to structural monitoring applications on vehicles. The design of the interfaces of the electric, magnetic, and structural coupled systems forming the harvester are described including dynamic modeling and simulation. Finally, the results of laboratory tests were compared with the harvester dynamic response calculated through numerical simulations, and a good correspondence was obtained.

Piezoelectric devices for energy harvesting in building structures

Devices that convert vibration energy into electricity and are capable of its accumulation (energy harvesting) are very promising both in mechanical engineering (damping oscillations with the conversion of excess energy into electricity) and in electronics and the environment (systems for energy storage and replenishment). That systems convert extra motion of engineering devises into electrical energy used for their autonomous operation or for power supply of other devices [1]. Another application is portable electronics, where energy storage devices can power or charge mobile phones or other devices. When energy sources are limited, energy harvesting plays an important role in the environment.&#x0D; Energy harvesting as a separate direction began to develop in the 1990s. Human, bicycle, water flow, low-frequency oscillations in mechanisms, etc. can be used as sources of mechanical energy for the piezoelectric transducer. Usually, due to steady oscillations, piezoelectric elements produce alternating electric current, showing the greatest efficiency at resonant frequencies. Most piezoelectric power sources produce power of the order of milliwatts, which is small enough for system use but sufficient for portable devices. Piezoelectric systems can convert the movement of the human body, such as the movement of legs and arms, shocks and blood pressure to obtain energy from implanted or portable sensors. Piezoelectric elements are built into running and walking roads, shoes, pavement, etc. One of the priority areas of research is the development of autonomous wireless sensors that receive energy from the measured signal, or use other ways to obtain mechanical energy. Their use becomes relevant in atypical tasks - measuring oscillations in hard-to-reach places of rotating mechanisms, seismic sensors and so on. Smart roads can play an important role in electricity generation. The incorporation of piezoelectric material into the road can convert the pressure exerted by moving cars into voltage and current.

Dynamic characteristics of Mn-Cu high damping alloy subjected to impact load

Mn-Cu high damping alloy is a twin-type damping alloy. Owing to its martensite twin structure at room temperature, it can convert vibration energy into heat energy, thereby reducing vibration. Although essentially a nonlinear elastic material, Mn-Cu damping alloys are treated as linear elastic materials in current engineering practice. However, introducing a constant damping coefficient alone will produce significant errors when modeling vibration reduction characteristics of the material, especially under impact loading. In this study, vibration test was performed on Mn-Cu damping alloy cantilever beam subjected to an impact load and deviation between the test result and the one of existing modeling method was analyzed. A generalized fractional-order Maxwell model was established to describe the nonlinear constitutive relation of the Mn-Cu damping alloy. Then, the model was extended to the three-dimensional state and a secondary development was performed. Finally, various applications for the damping alloy were explored and the effects of the damping alloy on the vibration characteristics of composite cantilever beam structures subjected to impact loads were investigated with the aim of better understanding the dynamic characteristics and improving the effectiveness of vibration reduction applications using Mn-Cu damping alloy in the future.

A Self-Powered and Highly Accurate Vibration Sensor Based on Bouncing-Ball Triboelectric Nanogenerator for Intelligent Ship Machinery Monitoring.

With the development of intelligent ship, types of advanced sensors are in great demand for monitoring the work conditions of ship machinery. In the present work, a self-powered and highly accurate vibration sensor based on bouncing-ball triboelectric nanogenerator (BB-TENG) is proposed and investigated. The BB-TENG sensor consists of two copper electrode layers and one 3D-printed frame filled with polytetrafluoroethylene (PTFE) balls. When the sensor is installed on a vibration exciter, the PTFE balls will continuously bounce between the two electrodes, generating a periodically fluctuating electrical signals whose frequency can be easily measured through fast Fourier transform. Experiments have demonstrated that the BB-TENG sensor has a high signal-to-noise ratio of 34.5 dB with mean error less than 0.05% at the vibration frequency of 10 Hz to 50 Hz which covers the most vibration range of the machinery on ship. In addition, the BB-TENG can power 30 LEDs and a temperature sensor by converting vibration energy into electricity. Therefore, the BB-TENG sensor can be utilized as a self-powered and highly accurate vibration sensor for condition monitoring of intelligent ship machinery.

Steady state response analysis for a switched stiffness vibration control system based on vibration energy conversion

A novel semi-active vibration control concept with a serial-switch-stiffness-system was previously presented in our work. Differing from conventional vibration control systems, this system does not dissipate but converts vibration energy as potential energy stored in springs and then reacts against external disturbance. As a piecewise linear system, whether or not energy conversion limit happens is an interesting nonlinear dynamic issue related to the systems steady state response. This paper formulates this issue in depth using the approach called equivalence in control. The systems control force represented by the converted vibration energy is approximately decomposed into two portions. One is responsible for low-frequency free response and the other for high-frequency switching response. An equivalent linear system suffering from a decomposed high-frequency switching force is obtained instead of the original switched system. The steady state response of the disturbed system can be delivered through linear superposition as executed in a linear system. Energy conversion limit occurring in the system under a harmonic disturbance is numerically shown by means of fast Fourier transformation. Analytical formulation and numerical simulation for open- and closed-loop control of the system are further carried out, respectively. The results give that the proposed approach is capable of solving the stead state response of the switched system accurately, and meanwhile, energy conversion limit occurs in the vibration control system indeed. Experimental discussion is also executed.

Modeling and Analysis of Multiple Attached Masses Tuning a Piezoelectric Cantilever Beam Resonant Frequency

Mechanical vibrations have been an important sustainable energy source, and piezoelectric cantilevers operating at the resonant frequency are regarded as one of the effective mechanisms for converting vibration energy to electricity. This paper focuses on model and experimental investigations of multiple attached masses on tuning a piezoelectric cantilever resonant frequency. A discrete model is developed to estimate the resonant frequencies’ change of a cantilever caused by multiple masses’ distribution on it. A mechanism consisted of a piezoelectric cantilever with a 0.3 g and a 0.6 g movable mass along it, respectively, is used to verify the accuracy of the proposed model experimentally. And another mechanism including a piezoelectric cantilever with two 0.3 g attached masses on it is also measured in the designed experiment to verify the discrete model. Meanwhile, the results from the second mechanism were compared with the results from the first one in which the single attached mass is 0.6 g. Two mechanisms have wildly different frequency bandwidths and sensitivities although the total weight of attached masses is the same, 0.6 g. The model and experimental results showed that frequency bandwidth and sensitivity of a piezoelectric cantilever beam can be adjusted effectively by changing the weight, location, and quantity of attached masses.

Longitudinal vibration wave in the composite elastic metamaterials containing Bragg structure and local resonator

In this paper, a novel composite acoustical hyperstructure of Bragg structure with local resonator is investigated theoretically for discussing the scattering performance of longitudinal vibration wave, its bandgaps are calculated using the established mathematical model. For confirming the veritable existence of bandgap and verifying the correctness of established mathematical model, the transmission spectrum of composite acoustical hyperstructure is also studied using finite-element method, and comparing the vibration transmission spectrum with bandgaps, the results indicate that the established theoretical model can correctly predict longitudinal wave bandgaps. Moreover, the bandgaps and modes shapes are calculated and compared with an unalloyed Bragg structure for probing the dispersion mechanics of composite acoustical hyperstructure, it turned out that local resonator can add one bandgap at the base of Bragg structure and the total bandgaps can be broadened. Further, for discussing the effect of spring of local resonator on bandgaps, bandgap of local resonator with different spring is calculated, the results showed that the total width of BG is larger when Young’s modulus is 1E and 16E, the total width are 772.48 and 774.30 Hz, respectively; as Young’s modulus is 0.5E and 2E, the width of BG are lower, 753.79 and 754.23 Hz, respectively. In view of longitudinal vibration wave inducing structural distortion and vibration energy conversion, the dynamic properties of composite acoustical hyperstructure are studied via strain energy density, the results indicate that reaction formation of local resonator can dissipate strain energy, when the local resonator is not activated (or waveless along with Bragg structure), un-dissipation strain energy.

Harvesting vibration energy to piezo-catalytically generate hydrogen through Bi2WO6 layered-perovskite

Vibration energy sources are nearly ubiquitous in our daily life, for instance, walking, automobile engine, heartbeat, noise, etc., occurring almost whenever and wherever possible. It would be an interesting and exciting breakthrough in the field of energy, if all these energies could be gathered and utilized. Piezoelectric materials make it possible, which can convert vibration energy into electric energy by inducing positive and negative electric charges. Up to now, there has rarely reported on hydrogen generation by piezoelectric materials utilizing vibration energy. Here, an efficient piezo-catalytic hydrogen generation in the layered-perovskite bismuth tungstate (Bi 2 WO 6 ) nanoplates is carried out through harvesting vibration energy. The yield of hydrogen can achieve 1147.8 μmol g −1 after 6 h vibration with the rate of hydrogen generation of 191.3 μmol g −1 h −1 . The conduction band level of H + /H 2 is more positive than the minimum of conduction band of Bi 2 WO 6 nanoplates, enabling the reduction of water to generate hydrogen. Converting vibration energy into useful clean hydrogen energy can not only make use of waste energy, but also be expected to solve the problem of energy shortage, which is potential in developing the clean hydrogen energy in future. • Vibration energy was harvested to piezo-catalytically generate hydrogen. • The yield of hydrogen can achieve 1147.8 μmol g −1 after 6 h. • The piezo-catalysis provides potential application in hydrogen generation utilizing the natural vibration energy.