scholarly journals Modal Analysis and Experiment of a Lycium barbarum L. Shrub for Efficient Vibration Harvesting of Fruit

Agriculture ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 519
Author(s):  
Jian Zhao ◽  
Satoru Tsuchikawa ◽  
Te Ma ◽  
Guangrui Hu ◽  
Yun Chen ◽  
...  
Keyword(s):  
Resonance Frequency ◽  
Modal Analysis ◽  
3D Model ◽  
Fem Simulation ◽  
Shape Parameters ◽  
Lycium Barbarum ◽  
Acceleration Sensors ◽  
Harvesting Method ◽  
Physical Tests ◽  
Low Efficiency

The most common harvesting method of Lycium barbarum L. (L. barbarum) is manual harvesting, resulting in low efficiency and high cost. Meanwhile, the efficiency of vibration harvesting, which is considered an efficient mechanical harvesting method, can be significantly improved if the optimized resonance frequency of the shrub can be obtained. To vibration harvest fruit efficiently, a 3D model of the shrub was established based on measurements of the shape parameters, and material mechanics models of the branches were established based on physical tests. The modal analysis of the shrub based on finite element method (FEM) simulation was performed to obtain the range of resonance frequency, and the modal experiment of the shrub using acceleration sensors and an impact hammer was conducted to obtain the accurate resonance frequency. Based on the results of the modal analysis and experiment, the optimized resonance frequency was determined to be 2 Hz. The field experiment showed that the fruit fell off when the branches were vibrated at this frequency. The results provide the design basis for the efficient vibration harvesting of L. barbarum.

scholarly journals Modeling the Piezoelectric Cantilever Resonator with Different Width Layers

Sensors ◽  
2020 ◽  
Vol 21 (1) ◽  
pp. 87
Author(s):  
Zhenxi Liu ◽  
Jiamin Chen ◽  
Xudong Zou
Keyword(s):  
Resonance Frequency ◽  
Integrated Circuit ◽  
Silicon Oxide ◽  
Fem Simulation ◽  
Control Process ◽  
Design Tool ◽  
Piezoelectric Cantilever ◽  
Simulation And Experiment ◽  
Easy Integration ◽  
Tip Displacement

The piezoelectric cantilever resonator is used widely in many fields because of its perfect design, easy-to-control process, easy integration with the integrated circuit. The tip displacement and resonance frequency are two important characters of the piezoelectric cantilever resonator and many models are used to characterize them. However, these models are only suitable for the piezoelectric cantilever with the same width layers. To accurately characterize the piezoelectric cantilever resonators with different width layers, a novel model is proposed for predicting the tip displacement and resonance frequency. The results show that the model is in good agreement with the finite element method (FEM) simulation and experiment measurements, the tip displacement error is no more than 6%, the errors of the first, second, and third-order resonance frequency between theoretical values and measured results are 1.63%, 1.18%, and 0.51%, respectively. Finally, a discussion of the tip displacement of the piezoelectric cantilever resonator when the second layer is null, electrode, or silicon oxide (SiO2) is presented, and the utility of the model as a design tool for specifying the tip displacement and resonance frequency is demonstrated. Furthermore, this model can also be extended to characterize the piezoelectric cantilever with n-layer film or piezoelectric doubly clamped beam.

Dynamics Analysis of Refrigeration Compressor Based on Finite Element and Experimental Modes

2012 ◽  
Vol 499 ◽  
pp. 238-242
Author(s):  
Li Zhang ◽  
Hong Wu ◽  
Yan Jue Gong ◽  
Shuo Zhang
Keyword(s):  
Finite Element ◽  
Dynamic Response ◽  
Modal Analysis ◽  
Natural Frequency ◽  
High Precision ◽  
3D Model ◽  
Finite Element Models ◽  
Dynamics Analysis ◽  
Response Characteristics ◽  
Dynamic Response Characteristics

Based on the 3D model of refrigeration's compressor by Pro/E software, the analyses of theoretical and experimental mode are carried out in this paper. The results show that the finite element models of compressor have high precision dynamic response characteristics and the natural frequency of the compressor, based on experimental modal analysis, can be accurately obtained, which will contribute to further dynamic designs of mechanical structures.

scholarly journals Harmonic Resonance Identification and Mitigation in Power System Using Modal Analysis

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 4017
Author(s):  
Jure Lokar ◽  
Janja Dolenc ◽  
Boštjan Blažič ◽  
Leopold Herman
Keyword(s):  
Resonance Frequency ◽  
Modal Analysis ◽  
Systematic Approach ◽  
Harmonic Distortion ◽  
Mode Analysis ◽  
Sufficient Information ◽  
Network Nodes ◽  
Resonance Phenomena ◽  
Harmonic Resonance ◽  
Modal Resonance

Due to a rising share of power electronic devices in power networks and the consequent rise in harmonic distortion, impedance resonances are an important issue. Nowadays, the frequency scan method is used for resonance phenomena identification and analysis. The main disadvantage of the method is its inability to decouple different resonance phenomena. This means that the method is also unable to provide sufficient information about the effects that the parameters of network elements have on different resonance phenomena. Furthermore, it was also noted that despite the fact that the harmonic resonance mode analysis is well described in the literature, there is a lack of systematic approach to the analysis procedure. Thus the main objective of this paper is to address this disadvantage and to propose a systematic approach to harmonic resonance analysis and mitigation, utilizing modal analysis. In the first part of the paper, dominant network nodes in terms of resonance amplification of harmonics are determined. This is done by analysis of the eigenvalues of the network admittance matrix. Using the eigenvalue analysis results, key parameters of network elements involved in a specific resonance are determined next. This is performed by calculating the critical mode (i.e., the mode that experiences resonance) sensitivity coefficients with respect to network parameters. In the second part of the paper, the procedure for modal resonance frequency shift is presented. The shift is performed by changing the value of a selected parameter so that the modal resonance frequency matches the desired resonance frequency value. The parameter value is calculated with the Newton–Rhapson method. Presented analysis considers both parallel and series resonances. The effectiveness of the proposed method is demonstrated on an actual industrial-network model.

scholarly journals Metal rings and discs Matlab/Simulink 3D model for ultrasonic sandwich transducer design

2012 ◽  
Vol 44 (3) ◽  
pp. 287-298 ◽  
Author(s):  
I. Jovanovic ◽  
D. Mancic ◽  
V. Paunovic ◽  
M. Radmanovic ◽  
V.V. Mitic
Keyword(s):  
Resonance Frequency ◽  
3D Model ◽  
Mechanical Impedance ◽  
Analytical Models ◽  
Resonant Frequencies ◽  
Matlab Simulink ◽  
Simulink Model ◽  
Metal Rings ◽  
Resonant Modes ◽  
Transducer Design

Metal-endings are integral part of different ultrasonic sandwich transducers. In this paper a new Matlab/Simulink 3D model of the finite metal rings and discs of various dimensions is realized. With this model, which describes both the thickness and the radial resonant modes, and the coupling between them, mechanical impedance of the sample can be easily computed. Resonance frequency-length curves for rings and disks with various materials and for different selected dimensions are given. Also, comparisons of the different approaches in determining of their resonant frequencies are shown. The proposed Matlab/Simulink model requires simpler implementation than other analytical models. That enabled modifying of 1D theory and simplified modelling and projecting of the ultrasonic sandwich transducers with short-endings. Finally, the computed and experimental results are compared.

Investigation on Resonance Effects of Closely Resonating Nano-Pillars Attached to SAW Resonator

2011 ◽  
Vol 403-408 ◽  
pp. 1183-1187
Author(s):  
N. Ramakrishnan ◽  
Harshal B. Nemade ◽  
Roy Paily Palathinkal
Keyword(s):  
Acoustic Wave ◽  
Resonance Frequency ◽  
Frequency Shift ◽  
Fem Simulation ◽  
Mass Loading ◽  
Loading Effect ◽  
Resonance Effects ◽  
Additional Information ◽  
Resonance Frequency Shift ◽  
Small Change

Surface acoustic wave (SAW) sensors form an important class of micro sensors in the microelecto mechanical systems (MEMS) family. Mass loading effect of a sensing medium is one of the prime sensing principles in SAW sensors. Recently we reported mass loading effect of high aspect ratio nano-pillars attached to a SAW resonator. We observed increase in resonance frequency of the SAW resonator in addition to the general mass loading characteristics. We concluded that when the resonance frequency of the pillar is equal to the SAW resonator frequency, the resonance frequency shift caused by mass loading of pillar tends to a negligible value. When such resonating pillars are used as sensing medium in SAW sensors, even a very small change in the dimension of the pillar will offer significant resonance frequency shift. Accordingly, high sensitive SAW sensors can be developed. However in practice it’s quite difficult to manufacture nano-pillars with accurate dimensions such that they resonate with SAW resonator. There is more probability that the pillars may closely resonate with SAW device and offer mass loading. In the present work we have extended our earlier work and performed finite element method (FEM) simulation to study the insight physics of the closely resonating pillars and their effects on acoustic wave propagating on SAW substrate. In this paper we present the discussion on the resonance effects of typical closely resonating pillars on resonance frequency spectrum of the SAW resonator and observations in the pressure wave at the contact surface of the pillar and SAW resonator substrate. It is observed that when the nano-pillars closely resonate with SAW resonator, the pillar oscillations combine with waves propagating in the substrate and introduce beat frequencies. The results and discussion of this paper adds additional information in designing SAW based coupled resonating systems.

Finite Element Modelling of Air-Coupled Circular Capacitive Micromachined Ultrasonic Transducer for Anodic Bonding Process using SOI Wafer

2021 ◽  
Author(s):  
Gurpreet Singh Gill ◽  
Sanjay Kumar ◽  
Ravindra Mukhiya ◽  
Vinod Kumar Khanna
Keyword(s):  
Finite Element ◽  
Resonance Frequency ◽  
Glass Substrate ◽  
Ultrasonic Transducer ◽  
Fem Simulation ◽  
Silicon On Insulator ◽  
Anodic Bonding ◽  
Free Standing ◽  
Design Flexibility ◽  
Capacitive Micromachined Ultrasonic Transducer

Abstract Capacitive Micromachined Ultrasonic Transducer (CMUT) provides an alternative to commercial piezoelectric-based ultrasonic transducers due to its wide bandwidth, improved efficiency, sensitivity, and design flexibility [1, 2]. In this paper, Finite Element Method-based design and simulations of circular capacitive micromachined ultrasonic transducer (CMUT) is presented. The FEM simulation of air-coupled CMUT was accomplished by using MEMCAD tools CoventorWare® and COMSOL™. The resonance frequency of 3.9 MHz was achieved for the designed circular CMUT device. A favourable agreement was found for the resonance frequency and pull-in voltage of the device using MEMSCAD tools and analytical calculations. For the proposed CMUT design, a circular cavity will be formed inside the glass substrate. Then, a free-standing membrane will be released using active layer of silicon-on-insulator (SOI) wafer. The bulk silicon of SOI wafer will be removed after bonding it on the glass substrate using anodic bonding technique as described in fabrication process flow for CMUT.

Finite Element and Modal Analysis for Connecting Rod Used in Piston Type Air Compressor

2014 ◽  
Vol 945-949 ◽  
pp. 3-6
Author(s):  
Xiao Xu Liu ◽  
Min Chen
Keyword(s):  
Finite Element ◽  
Stress Analysis ◽  
Modal Analysis ◽  
Dynamic Characteristic ◽  
3D Model ◽  
Static Strength ◽  
Connecting Rod ◽  
Air Compressor ◽  
Finite Element Stress Analysis ◽  
Finite Element Stress

The static strength and dynamic characteristic of connecting rod used in model 10/7 L type air compressor with double actions was studied, the 3D model of connecting rod was established by SolidWorks software, and the finite element stress analysis and modal analysis were done by ANSYS; the analysis results can be used as the base to improve the design of the connecting rod.

Modeling and Modal Analysis on Capacitive Micromachined Ultrasound Transducers

2014 ◽  
Vol 620 ◽  
pp. 300-303
Author(s):  
Yan Li ◽  
Pei Yu Zhang
Keyword(s):  
Modal Analysis ◽  
Thin Plate ◽  
Fem Simulation ◽  
Ultrasonic Transducers ◽  
Side Length ◽  
Ultrasound Transducers ◽  
Resonant Frequencies ◽  
Capacitive Micromachined Ultrasonic Transducers ◽  
Length Width ◽  
Vibration Modal

The capacitive micromachined ultrasonic transducers with square and rectangular membranes were modeled for FEM simulation. The membrane is modeled as a thin plate clamped on all sides. Resonant frequencies and vibration modal analysis were carried out. The modes of CMUT with square and rectangular membranes are different. It can be basis for building CMUTs’ structure. Moreover, the resonant frequencies will vary with different side length and ratio of length/width of membrane.

Vibration Modal Analysis of Involve Gear with Asymmetric Tooth Profile and Double Pressure Angles

2011 ◽  
Vol 418-420 ◽  
pp. 1748-1751
Author(s):  
Wei Li ◽  
Ning Liu ◽  
Ning Li ◽  
Yan Jun Liu ◽  
Liang Ma
Keyword(s):  
Modal Analysis ◽  
3D Model ◽  
Natural Frequencies ◽  
Reference Value ◽  
Tooth Profile ◽  
Mode Shapes ◽  
Ansys Software ◽  
Dynamic Design ◽  
Dynamic Performances ◽  
Vibration Modal

The 3D model of gear with asymmetric profile and double pressure angles is built by the autodesk inventor software. It is imported and analyzed by the ANSYS software. Then each order natural frequencies and mode shapes are obtained. So resonance and harmful mode shapes can be avoided, and dynamic performances of gear with asymmetric profile and double pressure angles is improved. This paper has a certain reference value for the dynamic design of other types of gears.

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