International Journal of Applied Electromagnetics and Mechanics - Volume 64, issue 1-4

Authors: Desideri, Daniele | Bernardo, Enrico | Corso, Alain Jody | Doria, Alberto | Maschio, Alvise | Moro, Federico | Pelizzo, Maria Guglielmina

Article Type: Research Article

Abstract: In view of high temperature applications, c-axis oriented aluminium nitride films on aluminium substrate were produced by magnetron sputtering at low pressure (0.3 and 0.5 Pa) and different values of nitrogen concentration. XRD data show the highest intensity of (002) diffraction peak with nitrogen concentration of 0.4, and the peak value decreases when the nitrogen concentration moves away from 0.4. The transverse piezoelectric constant (absolute value) was determined for all conditions, the highest values observed with nitrogen concentration of 0.4 (in agreement with XRD data) and 0.8, with a slight preference for 0.4. These new experimental data and the presence …of the two peaks of similar amplitude on the estimated transverse piezoelectric constant are useful information for the identification of good practical operative conditions for AlN films sputtered on aluminium, basic structure for the development of high temperature piezoelectric transducers. Show more

Keywords: Aluminium nitride, magnetron sputtering, transverse piezoelectric constant

DOI: 10.3233/JAE-209370

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 64, no. 1-4, pp. 607-613, 2020

Authors: Chen, Yuansheng | Zhao, Pengcheng | Wang, Hao | Qiu, Jinhao | Yang, Guowen

Article Type: Research Article

Abstract: Piezo driver for piezoelectric bimorph actuators is the key component for micro-positioning application. Hysteresis nonlinearity of piezoelectric bimorph actuators limits the performance of micro-positioning systems. A novel piezo driver was developed with Prandtl-Ishlinskii (P-I) model and correction network. The combination of P-I model and correction network can describe the rate-dependent hysteresis. Experiments were performed to validate the proposed piezo driver. The results show that the piezo driver can compensate the hysteresis of the piezoelectric bimorph actuator in the frequency range of 0.1 Hz to 10 Hz, and the accuracy of micro-positioning have been greatly improved.

Keywords: Piezoelectric bimorph actuator, hysteresis compensation, piezo driver

DOI: 10.3233/JAE-209371

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 64, no. 1-4, pp. 615-620, 2020

Authors: Zhao, Yingsong | Jomdecha, Cherdpong | Xie, Shejuan | Chen, Zhenmao | Qi, Pan | Liao, Shusheng | Uchimoto, Tetsuya | Takagi, Toshiyuki

Article Type: Research Article

Abstract: In this paper, the conventional database type fast forward solver for efficient simulation of eddy current testing (ECT) signals is upgraded by using an advanced multi-media finite element (MME) at the crack edge for treating inversion of complex shaped crack. Because the analysis domain is limited at the crack region, the fast forward solver can significantly improve the numerical accuracy and efficiency once the coefficient matrices of the MME can be properly calculated. Instead of the Gauss point classification, a new scheme to calculate the coefficient matrix of the MME is proposed and implemented to upgrade the ECT fast forward …solver. To verify its efficiency and the feasibility for reconstruction of complex shaped crack, several cracks were reconstructed through inverse analysis using the new MME scheme. The numerical results proved that the upgraded fast forward solver can give better accuracy for simulating ECT signals, and consequently gives better crack profile reconstruction. Show more

Keywords: Fast forward solver, multi-media element, crack shape reconstruction, eddy current test

DOI: 10.3233/JAE-209372

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 64, no. 1-4, pp. 621-629, 2020

Authors: Chen, Hucheng | Han, Wei | Qiu, Jinhao

Article Type: Research Article

Abstract: Better understanding of the characteristics of the traveling wave and three-dimensional trajectory related to motion on the surface of the stator is very important for the design and performance improvement of the ultrasonic motors. In this paper, an accurate finite element model of a single stator with a fully coupled piezoelectric layer was established at a moderate computational cost. The finite element model was verified by experimental test at the inverse resonance point. Based on this model, the traveling wave and three-dimensional trajectory of stator surface, including the influence of the input voltage on the phase and amplitude of the …displacements in three directions, are investigated. The results show that the trajectory of particles on the stator surface is an ellipse in three-dimensional space due to the phase differences between the three components of displacement in the radial, circumferential and axial directions. The amplitude of radial displacement is about 39.5% of that in the circumferential displacement, which should not be neglected. Show more

Keywords: Traveling wave vibration characteristic, ultrasonic motor, anti-resonance point, finite element model

DOI: 10.3233/JAE-209373

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 64, no. 1-4, pp. 631-638, 2020

Authors: Cai, Zhichao | Zhao, Zhenyong | Chen, Lan | Tian, Guiyun

Article Type: Research Article

Abstract: In this paper, a new electromagnetic acoustic resonance (EMAR) transducer is proposed for precise thickness measurement in specimen. The new EMAR is composed of a mirror symmetric coil (MSC) and a pair of Nd-Fe-B permanent magnets with the different polarity for enhancing the generation and detection of resonant signals. Firstly, a finite element model was established to simulate the distributions of Lorentz force produced by new EMAR and the resonant process of shear waves. Furthermore, the relationship between the frequency response characteristic of the new EMAR and the common EMAR were explored. Finally, to verify the performance of the EMAR, …several experiments were performed. Compared with the common EMAR transducer, the resonant amplitude of the new EMAR transducer was increased by 121.74% and the signal-to-noise ratio was increased by 28.35%, and the resonance frequency interval of the new EMAR was twice that of the common mode in the frequency domain simulation experiment, this advantage effectively reduced the error rate of measurement. The results show that the new EMAR transducer with mirror coil structure has higher accuracy in thickness detection of specimens. Show more

Keywords: Mirror symmetric coil, finite element simulation, frequency response characteristics, signal-to-noise ratio

DOI: 10.3233/JAE-209374

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 64, no. 1-4, pp. 639-647, 2020

Authors: Chen, Delei | Wang, Cheng | Lai, Xiongming | Zhang, Huizhen | Li, Haibo | Chen, Jianwei

Article Type: Research Article

Abstract: In order to reduce the influence of ill-posed inverse on response prediction in the situation of unknown uncorrelated multiple sources load, a response prediction method based on elastic-net regularization in the frequency domain was proposed. This method utilized the linear relationship between known responses and the unknown responses instead of the transfer function to predict the response. Moreover, the elastic-net regularization model has two regularization parameters combining l1, l2 regularization to reduce the influence of ill-posed inverse. The experiment results on the data of acoustic and vibration sources on cylindrical shells showed that the elastic-net regularization in predicting response could …obtain higher accurate results compared with the method of transfer function and the method of ordinary least squares, and predict vibration response effectively and satisfy industrial requirements. Show more

Keywords: Multi-point vibration response prediction, elastic-net regularization, ill-posed, ordinary least squares

DOI: 10.3233/JAE-209375

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 64, no. 1-4, pp. 649-657, 2020

Authors: Liu, Dandan | Ma, Wu | Wang, Jie | Liu, Chongzhi | Tang, Chunrui

Article Type: Research Article

Abstract: The particle movement speed in the pipe of an existing dust measuring device is too small, and the detection in the center area of the pipe is not sufficiently sensitive. According to the intake mode of the cyclone separator, here a new side inlet pipeline is designed that is oriented from the incident mode of the straight pipe. An experimental model was established in Gambit2.4, and the numerical simulation was performed in Fluent6.3. Different dust particle diameters were simulated, and velocity cloud and pressure cloud diagrams of the middle position of the device pipe were obtained. Compared with the velocity …data of the straight tube and the side tube, the velocity value of the particle passing through the side tube was better than that of the straight tube. This improved the velocity of the particles and also reduced the settling of the particles. The probability of friction collision of the dust particles in the tube increased, meaning that their induced charge also increased. MATLAB was used to calculate the electrostatic induction, revealing that the charge of the particles in the improved device increased significantly. Therefore, the improved device can effectively improve the measurement accuracy of dust at low concentrations, and for small particle sizes. Show more

Keywords: Dust measurement, electrostatic induction, side inlet pipe, rotating attachment wall, data comparison

DOI: 10.3233/JAE-209376

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 64, no. 1-4, pp. 659-666, 2020

Authors: Azeem, Muhammad | Kim, Byungtaek

Article Type: Research Article

Abstract: This paper examines the influence of pole and slot combinations on the electromagnetic performance of the flux-switching permanent magnet (FSPMs) machine. For this purpose, first the production of air gap flux density in machine analytically discussed. Next, five different pole and slot combination are selected by using the knowledge of air-gap flux density expression. The performances of the different combinations are analyzed and compared using the finite element analysis (FEA), and optimal pole and slot combination is suggested. It is found that the pole and slot combination has a dominant effect on machine performance and needs to be considered during …the design stage. Show more

Keywords: Flux switching permanent magnet machine, air gap flux density, pole and slot combination, performance analysis

DOI: 10.3233/JAE-209377

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 64, no. 1-4, pp. 667-674, 2020

Authors: Hu, Jiaming | Bai, Baodong | Chen, Dezhi

Article Type: Research Article

Abstract: In this paper, the electron-molecule collision ionization is added to field emission under non-vacuum conditions, and the change of emission current caused by vacuum adjustment in field emission of carbon nanotubes is explained. The field emission current density equation under non-vacuum conditions is established. Through the theoretical analysis and the processing of experimental data, it can be concluded that when other variables are controlled unchanged, the change of pressure will affect the concentration of gas molecules in the air and the collision probability with electrons, then the density of emission current is changed. The study has a certain reference value …for the application of field emission in low vacuum and atmospheric pressure. Show more

Keywords: Field emission, carbon nanotube arrays, vacuum degree

DOI: 10.3233/JAE-209378

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 64, no. 1-4, pp. 675-683, 2020

Authors: Feng, Sheng | Tu, Jun | Wei, Shilin | Chi, Yongbin | Zhang, Xu | Song, Xiaochun

Article Type: Research Article

Abstract: The axial stress of high strength bolts for bridges affects the service life directly, it is necessary to measure it regularly. Based on the theory of acoustic elasticity and combination of longitudinal and shear waves, a new theoretical analysis method is proposed. The stressed and non-stressed areas of bolt are separated, and the derived formula only use the flight time and difference of acoustoelastic coefficients to get axial stress. Further, the preload experiments with high strength bolts of grade 8.8S and 10.9S is designed, the experimental results show that the proposed method is applicable to the axial stress of the …bridge bolts with any specifications, material and different screwing depth used in this paper, the effect of elastic deformation on the flight time is eliminated, and the measuring error is within 5%. Show more

Keywords: High strength bolt, axial stress, ultrasonic testing, piezoelectric ultrasonic

DOI: 10.3233/JAE-209379

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 64, no. 1-4, pp. 685-692, 2020