International Journal of Applied Electromagnetics and Mechanics - Volume 57, issue 4

Authors: Zhang, Xiao | Cao, Quanliang | Li, Xiaoxiang | Yi, Lei | Ma, Jimin | Li, Xinhua | Li, Liang

Article Type: Research Article

Abstract: In order to investigate the deformation behavior of tube in electromagnetic forming with external die, in this paper, a numerical model based on the equivalent circuit method and finite element method was developed to simulate the tube deforming process, which was implemented through the coupling of MATLAB 2015a and ANSYS 15.0. Results showed that the deformation behavior of tube, including deformation depth and end flowing, is influenced by the distribution of Lorentz force, and the effect of the external die, which includes the restraining of radial expansion of tube, and the friction force generated from the contact of tube and …die. Show more

Keywords: Electromagnetic forming, current filament method, finite element method, lorentz force distribution, friction force

DOI: 10.3233/JAE-180019

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 57, no. 4, pp. 377-388, 2018

Authors: Deng, Fangxiong | Cao, Quanliang | Han, Xiaotao | Chen, Qi | Li, Liang

Article Type: Research Article

Abstract: Electromagnetic pulse welding (EPW) is an effective way to realize the connection of two different kinds of metal materials via pulsed electromagnetic forces. To improve the welding performance, a new EPW process with a dual-stage coil system is proposed for joining aluminum sheets in this paper, in which one coil is used to generate a pulsed magnetic field with a short pulse width for inducing an eddy current in the aluminum sheet, while the other one is applied to generate a background magnetic field with a relatively long pulse width for increasing electromagnetic force acting on the aluminum sheet. The …EPW system has been designed and implemented based on the simulation results using the finite element method, with considering the effects of coil shape, the number of coil turns and the discharge parameters. Finally, experiments are carried out to validate the feasibility of the EPW system. Show more

Keywords: Electromagnetic pulse welding, pulse magnetic field, background magnetic field

DOI: 10.3233/JAE-180006

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 57, no. 4, pp. 389-398, 2018

Authors: Wang, Si-Yuan | Song, Wan-Li | Li, Hong-Liang | Wang, Na

Article Type: Research Article

Abstract: In investigating magnetorheological (MR) brakes, it is well known that the braking torque is the important factor in the structure’s design and the temperature of MR fluid in the brake is required to be within the operating range. In addition, the stress condition of the component changes obviously in the combined effects of force and thermal load which may result in structural damage. This study aims to propose a multi-cylindrical MR brake with a high-torque and investigate it more comprehensively in multi-field simulation. To achieve this goal, the mathematical model of the braking torque and the computing platforms of Maxwell …and Ansys workbench are adopted to explore the influence of the exciting current and the number of braking cylinders on the braking performance, as well as the temperature and structural stress distribution of the braking cylinder during braking. The magnetic analysis shows that the proposed magnetic circuit is reasonable. The relationship between braking torque and exciting excitation current is nonlinear. The thermal simulation analysis shows that the temperature of MR brake remains within operating range of MR fluid after braking. The structural stress analysis shows that the contact position of braking cylinder and magnetism-insulator is the easiest place to break. Show more

Keywords: Braking performance, magnetic analysis, multi-cylindrical MR brake, stress distribution, thermal simulation

DOI: 10.3233/JAE-170149

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 57, no. 4, pp. 399-414, 2018

Authors: Zhang, Yuanyuan | Pang, Huaji | Liu, Bing | Zhang, Qilin | Song, Lin | Lu, Xue

Article Type: Research Article

Abstract: This paper based on Barrick’s formulations and Wait’s formulations, we analyzed the lightning vertical electric field and it is derivative in the time domain along rough sea surface. Furthermore, we discussed that it effects on Time-of-Arrival (ToA)-based lightning location systems (LLS). We found that the wave-shape and time-delay of the vertical electric field can be significantly affected when propagates along rough the sea surface. The rough sea surface has a few effect on the magnitude of the vertical electric fields. With the observation distance increase, the rise time of the wave-shape becomes long with the increasing of the wind speed. …The peaks of the field derivative obviously decrease with the increasing of the wind speed, and the farther observation distance is, the stronger attenuation is. The time-delay of the field derivative increases as the wind speed increases. The observed time-delay resulting from the propagation along rough sea surface might impact the location accuracy of ToA-based LLS. Show more

Keywords: Lightning vertical electric field, rough sea surface, Qingdao buoy station

DOI: 10.3233/JAE-170139

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 57, no. 4, pp. 415-425, 2018

Authors: Karaman, Ozan | Gümüşay, Mehmet | Demirci, Emine Afra | Kaya, Adnan

Article Type: Research Article

Abstract: Pulsed electromagnetic fields (PEMF) and pulsed radio frequency energy (PRFE) have been shown to accelerate wound healing process due to its ability to stimulate cellular proliferation. However, comparative efficacy of PEMF and PRFE on an in vitro wound healing study has yet to be studied. The present study examined the effect of PEMF and PRFE on an in vitro wound healing model developed by using 3T3 mouse fibroblasts. Cells were exposed to PEMF (75 Hz frequency, square waveform, and 1-mT magnetic field) and PRFE (27.12 MHz, Phase-shift keying (PSK), and 13-dBm amplitude signal) for 5 hours. The migration …rates of 3T3 fibroblasts were determined by capturing images at time points of 0, 12, 24, 48, and 72 hours. Cell proliferation was also quantified. The results of the migration and proliferation assays showed that PEMF and PRFE applied groups had significantly greater cell proliferation and migration compared to control group. In addition, PRFE application showed significantly faster wound area closure compared to PEMF application. Show more

Keywords: Pulsed radio frequency energy (PRFE), pulsed electromagnetic fields (PEMF), wound healing, rectangular spiral applicator

DOI: 10.3233/JAE-170129

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 57, no. 4, pp. 427-437, 2018

Authors: Yang, Zhaoshu | He, Zhongbo | Yang, Fengbiao | Rong, Ce | Cui, Xinhan

Article Type: Research Article

Abstract: When large stroke of giant magnetostrictive actuator (GMA) is desired, it usually requires large number of turns in coil to generate sufficient magnetic field and therefore induce a considerable inductance in actuator. In this paper, a specific driving method is proposed for electro-hydraulic servo valve based on large inductance GMA. To begin with, a more reasonable model for the dynamics of driving coil is proposed and identified using Particle Swarm Optimization (PSO); then a specific half-SPWM driving mode is proposed taking advantages of this considerable inductance. The multi-coupled model for the overall servo valve is set up and simulated in …a joint environment of Simulink and AMESim; a prototyped switching converter based on Micro Controller Unit (MCU) and Insulated-Gate Bipolar Transistor (IGBT) is developed, a series of displacement and power tests are conducted. Both simulation and test results verify the advantages of our design, compared with continuous driver the proposed method drives the coil with less power consumption and a more compact structure; compared with traditional Sinusoidal Pulse Width Modulation (SPWM) driving mode, this method generates a smoother wave using less switch number and less switching losses. Show more

Keywords: Magnetostrictive actuator, power supply, electro-hydraulic servo valve

DOI: 10.3233/JAE-170116

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 57, no. 4, pp. 439-456, 2018

Authors: Borsenberger, Marc | Benabou, Abdelkader | Baudouin, Cyrille | Bigot, Régis | Faverolle, Pierre | Mipo, Jean-Claude

Article Type: Research Article

Abstract: Magnetic parts are usually composed of a stack of electrical steel laminations to reduce the eddy current losses. However, for cost reasons or for specific applications the magnetic core can be made from massive steel and thus manufactured with adapted processes such as forging. Such process may lead to inhomogeneous and degraded magnetic properties. Therefore, this study proposes a specific device for characterizing magnetic properties of samples which are to be representative of a massive part. The measure is based on the Faraday’s equation to determine the magnetic flux density and the Hall effect to estimate the magnetic …field inside the sample. Practically this is realized with classical components such as Hall probes, a secondary winding and an electromagnet device. However their combination is unique to perform magnetic characterization on massive samples, which are less affected by the sampling technique and may have anisotropic properties. The device is dimensioned thanks to FE-Simulation and validated according repeatability, sensitivity and trueness analysis. Eventually the characterization is performed on samples with different material parameters showing the effect of the grain size on the specific losses. The expected effect of the grain flow on magnetic properties is however not proven yet. Show more

Keywords: FE-Simulation, magnetic characterization, massive sampling, material properties

DOI: 10.3233/JAE-170108

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 57, no. 4, pp. 457-472, 2018