scholarly journals Modal Analysis of 27 mm Piezo Electric Plate for Small-Scale Underwater Sonar-Based Navigation

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
M. O. Afolayan ◽  
D. S. Yawas ◽  
C. O. Folayan ◽  
S. Y. Aku
Keyword(s):  
Resonance Frequency ◽  
Modal Analysis ◽  
Robotic Fish ◽  
Small Scale ◽  
Simulation Process ◽  
Antiresonance Frequency ◽  
Input Load ◽  
Ultrasonic Transmitters ◽  
Piezo Electric

This work presents progress towards the development of a small-scale, purely sonar-based navigation device for a robotic fish (~394 mm long). Aperture overloading of small (5 mm diameter) ultrasonic transmitters does not allow them to be used effectively inside water. A test on a 27 mm diameter buzzer piezo plate shows promising performance under water at frequencies from 4.5 kHz to 80 kHz. ANSYS-based simulation was therefore used to find modal frequencies at higher frequencies so as to optimize this encouraging result. The simulation process also discovered several antiresonant frequencies such as 38.5 kHz, 54 kHz, and 57.5 kHz. All frequencies above the 8th harmonic (10,589.02 Hz) are out of phase with the input load except a resonance frequency of 42.5 kHz and an antiresonance frequency of 56.5 kHz. Also, the first harmonic (1,648.73 Hz) is the only frequency that gave a nodal deformation.

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.

The Study on Circular Tool of Ultrasonic Cutting

2013 ◽  
Vol 765-767 ◽  
pp. 92-95
Author(s):  
Yun Dian Zhang ◽  
Liang Fang ◽  
Zhi Ping Lu ◽  
Jia Ying Yu
Keyword(s):  
Differential Equation ◽  
Composite Materials ◽  
Resonance Frequency ◽  
Modal Analysis ◽  
High Precision ◽  
Processing Efficiency ◽  
Working Principle ◽  
High Processing ◽  
Ultrasonic Cutting

The ultrasonic cutting of composite materials has the advantages such as high processing efficiency, high precision and non-pollution. The working principle of ultrasonic cutting is studied. The structure of circular tool is designed. The differential equation of tool frequency is established. The resonance frequency of tool is solved. Modal analysis is conducted for circular tool through ANSYS and the results are compared through tests.

scholarly journals Spatio-temporal structure of Alfvén waves excited by a sudden impulse localized on an L-shell

2012 ◽  
Vol 30 (7) ◽  
pp. 1099-1106 ◽  
Author(s):  
D. Yu. Klimushkin ◽  
P. N. Mager ◽  
K.-H. Glassmeier
Keyword(s):  
Resonance Frequency ◽  
Temporal Structure ◽  
Alfven Wave ◽  
Energy Concentration ◽  
Small Scale ◽  
Source Surface ◽  
Local Resonance ◽  
Sudden Impulse ◽  
Magnetic Shell ◽  
Spatio Temporal

Abstract. This paper is concerned with the spatial structure and temporal evolution of the azimuthally small scale Alfvén wave generated by a sudden impulse concentrated on a given magnetic shell. At the outset, both poloidal and toroidal components are present in the wave's magnetic field. The oscillation in the poloidal component on a given magnetic shell is a superposition of two monochromatic oscillations, one with the local resonance frequency on this shell, and the other with the frequency corresponding to the resonance frequency on the source surface. The superposition of these two oscillations leads to beating. Due to phase mixing, the poloidal component of the oscillation decreases with time down to zero, transferring its energy to the toroidal component. Beating in the toroidal component is less pronounced. As time elapses, energy concentration near the source magnetic shell occurs with the frequency of the oscillation corresponding to the Alfvénic resonance frequency on this surface. Outside this thin region wave amplitudes become rather small at oscillation frequencies corresponding to the local resonance frequency of the respective magnetic shell.

The Vibration and Modal Analysis of the Disc Brake

2013 ◽  
Vol 774-776 ◽  
pp. 78-81
Author(s):  
Fa Zong Li ◽  
Shui Guang Tong
Keyword(s):  
Numerical Simulation ◽  
Resonance Frequency ◽  
Modal Analysis ◽  
Natural Frequency ◽  
Vibration Mode ◽  
Noise Control ◽  
Simulation Method ◽  
Disc Brake ◽  
At Resonance ◽  
Numerical Simulation Method

The article analyzed the modal of disc brake, the intrinsic characteristics of each disc brake parts were obtained, using modal tests to verify the accuracy of the numerical simulation method; by comparing different vibration mode and natural frequency of the brake parts, predicting the frequency which vibration may occur, aiming at resonance frequency which is easy to occur, improving the structure of the disc brake to improve each order natural frequency, the resonance of the disc brake is effectively reduced, the braking noise was decreased, The study laid a foundation for vibration and noise control of the disc brake.

Design of a small scale wind energy harvester using piezo-electric cantilever generator for wireless flame sensor

2017 ◽  
Author(s):  
Conrado F. Ostia ◽  
Riza Marie G. Baylon ◽  
Charneth Noe Cate B. Pancho ◽  
Joseph Immanuel M. Talamera ◽  
Giovanni M. Viado ◽  
...  
Keyword(s):  
Wind Energy ◽  
Energy Harvester ◽  
Small Scale ◽  
Piezo Electric

A gray-box harmonic resonance frequency identification method of multiple-inverter-fed power system oriented to system designers

2021 ◽  
pp. 0309524X2110379
Author(s):  
Yue Wang ◽  
Yonggang Li ◽  
Yinan Yang ◽  
Binyuan Wu ◽  
Qiyu Liu ◽  
...  
Keyword(s):  
Power System ◽  
Resonance Frequency ◽  
Modal Analysis ◽  
Transfer Functions ◽  
Matrix Pencil ◽  
Identification Method ◽  
Matrix Pencil Method ◽  
Time Simulation ◽  
Frequency Identification ◽  
Harmonic Resonance

This paper presents a gray-box harmonic resonance frequency identification method of multiple-inverter-fed power system, which enables modal analysis oriented to system designers based on only frequency response data provided by diverse vendors or measured by frequency scanning. First, admittance transfer functions of all grid-connected inverters (GCIs) are fitted using Matrix Pencil Method-Vector Fitting (MPM-VF) combined method. Then, node admittance matrix (NAM) is formed according to the topology of whole system. Finally, harmonic resonance frequency along with changes in number of GCIs are identified by NAM-based modal analysis (MA). The proposed gray-box identification method is implemented in a typical multiple-inverter-fed power system. The correctness of harmonic resonance frequency identification results and the effectiveness of the presented method are verified by simulation results obtained in Matlab/Simulink platform and OPAL-RT digital real-time simulation platform. Based on the identification results, a more stable and better power quality multiple-inverter-fed power system can be built by system designers though avoiding the appearance of harmonic sources with corresponding resonance frequency.

Experimental Modal Analysis of Compressor Vibration Isolating System Based on LMS Test.Lab

2011 ◽  
Vol 121-126 ◽  
pp. 3283-3288
Author(s):  
Li Zhang ◽  
Hao Chen ◽  
Yan Jue Gong ◽  
Jing Wang
Keyword(s):  
Resonance Frequency ◽  
Modal Analysis ◽  
Natural Frequency ◽  
Single Layer ◽  
Experimental Modal Analysis ◽  
Impact Testing ◽  
Modal Parameters ◽  
Isolation System ◽  
Refrigeration Unit ◽  
Comparison Results

In order to reduce vibration and noise of the compressor used in small and medium-sized refrigeration unit, this paper designs different vibration isolating systems and carries out experimental modal analysis based on LMS Test. Lab Impact Testing software. The comparison results of modal parameters of four different vibration isolating systems show that the natural frequency of single-layer vibration isolating system is higher than that of non-isolation system and effectively avoids the second order resonance frequency. Furthermore the natural frequency of double-layer vibration isolating system has reduced due to the additional middle-mass. And the system's natural frequency decreases obviously with the increase of middle-mass which is far from resonance frequency and significantly improve the effect of vibration isolating system.

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