International Journal of Applied Electromagnetics and Mechanics - Volume 33, issue 3-4

Authors: Shen, Gongtian | Hu, Bin | Gao, Guangxin | Li, Yuntao

Article Type: Research Article

Abstract: The dynamic variation of amplitude and gratitude of metal magnetic memory (MMM) signals for a crack on a crane crossbeam was investigated during loading from 0 to 80KN. The result shows that the amplitude and gratitude of MMMT signals slowly increase from 0 to 50KN, quickly increase from 50 to 70KN and rapidly decrease from 70 to 80KN. The crack emerged result in the peak to peak value rapidly increasing and the shape of MMM signals change to sharp. The …stress released results in decreasing of the peak to peak of the amplitude and gratitude of MMM signals. MMM testing method can be used to monitor the activity of surface crack or damage in steel structure. Show more

Keywords: Metal magnetic memory (MMM) , crane, loading, crack, stress concentration

DOI: 10.3233/JAE-2010-1257

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 3-4, pp. 1329-1334, 2010

Authors: Takaya, Shigeru | Yamagata, Ichiro | Ichikawa, Shoichi | Nagae, Yuji | Aoto, Kazumi

Article Type: Research Article

Abstract: The relationships between neutron irradiation damage parameters, dose and He content, and the magnetic properties evaluated from the magnetic curves measured by a new developed vibrating sample magnetometer were investigated on type 316 stainless steel. A fast neutron reactor, JOYO, and a thermal neutron reactor, JRR-3, were used for irradiation. In addition to irradiation in each of the reactors, irradiations using the both of them, the coupling irradiation, were also conducted in this study. Irradiation in …different reactor and especially the coupling irradiation enabled us to evaluate the effects of dose and He content to the magnetic properties individually in a wide irradiation damage range hardly obtained by irradiation in only one reactor. As the result, it was revealed that the magnetic parameters, especially magnetization at 0.5/μ _{0} A/m and coercive force, have close relationships with dose. Furthermore, the comparison with the result of tensile test showed that these magnetic properties are related to irradiation hardening. On the other hand, any magnetic properties investigated in this study are not dependent on He content. These results show the possibility of nondestructive evaluation of dose and irradiation hardening based on the magnetic properties. Show more

Keywords: Nondestructive evaluation, neutron irradiation damage, dose, he content, vibrating sample magnetometer

DOI: 10.3233/JAE-2010-1258

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 3-4, pp. 1335-1342, 2010

Authors: Wang, Haitao | Zhang, Binqiang | Tian, G.Y. | Zhou, Deqiang | Wang, Ping | Li, Yong

Article Type: Research Article

Abstract: Pulsed Eddy Current (PEC) NDT has played a vital role in detection and classification of the surface and sub-surface defects in conductive structures. Normally, it uses peak values of the acquired transient field signals, and the combination of the feature values of the time of the peak to identify flaws with the help of Principal Component Analysis (PCA). However, it is found that the random noise undermines the classification results, because PCA works robustly only in …the time domain. In the light of this drawback, the fundamental and the first-harmonic components are investigated and taken as the new feature values in the frequency domain. Through the analysis of the feature values in both time and frequency domains, the influence of random noise is mitigated. Consequently, surface defects, subsurface defects and metal thickness changes are classified with much higher identification accuracy. Show more

Keywords: Pulsed Eddy Current, the fundamental component, the first harmonic component, defect

DOI: 10.3233/JAE-2010-1259

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 3-4, pp. 1343-1349, 2010

Authors: Hu, Bin | Li, Luming | Chen, Xing | Zhong, Liqiang

Article Type: Research Article

Abstract: The environmental magnetic field, the stress distribution and the materials are the influencing factors of Magnetic Memory Method (MMM). In order to discover the influencing rule of environmental magnetic field, different even magnetic field is offered during the period of Magnetic Memory (MM) signals occurred. It was found that the environmental magnetic field can change the MM signals magnitude, can not change the curve's profile ordinarily. If the certain magnetic field offered, the curve will be …reversed. So, if the environmental magnetic field was changed suitably, the best MM signals will be obtained. Three kinds of materials had been used in experiments to investigate the difference and influencing rule. The result reveals that material is an important role which determines the value of MM signals on condition that the stress and environmental al magnetic field are the same.It was derived from the experimental data that the percent of C influences MM signals in a certain rule but not linear. Those results are different with the existing MMM and improve the MMM evaluation system. The environmental magnetic field function mechanism can be explained by the phenomena of these experiments. Show more

Keywords: Magnetic memory method (MMM), influencing factors, stress concentration, environmental magnetic field, material

DOI: 10.3233/JAE-2010-1260

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 3-4, pp. 1351-1357, 2010

Authors: Xue, Chunxia | Zhang, Shanyuan | Shu, Xuefeng

Article Type: Research Article

Abstract: In this paper, a model is presented for a soft ferromagnetic rectangular thin plate which is coupled with a transverse magnetic field and is further under a transverse uniformly distributed load. The four edges of the plate are simply supported. Using the multiple scale method, the amplitude-frequency response equation in steady state is obtained. The amplitude-frequency response curves and the relevant time history curves are given by Matlab programs. Furthermore, the influence of the plate thickness, …magnetic field and magnetize coefficient on the vibration behaviour of the system is analyzed. Show more

Keywords: Soft ferromagnetic plate, magnetoelastic, Garlerkin method, principal resonance

DOI: 10.3233/JAE-2010-1261

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 3-4, pp. 1359-1364, 2010

Authors: Bramantya, Muhammad Agung | Takuma, Hiroki | Sawada, Tatsuo

Article Type: Research Article

Abstract: The magnetorheological response of magnetorheological fluids (MRF) results from the polarization induced in the suspended particles by application of an external magnetic field. We proposed a qualitative analysis of these effects by measuring properties of ultrasonic propagation. Hysteresis was appeared when magnetic field increased to and decreased from the certain value, 290 mT in our experiment. The change rate of the ultrasonic wave propagation velocity increased during the increasing process of the external magnetic …field. However, it was kept almost the same value during the decreasing process. Show more

Keywords: Magnetorheological fluids, ultrasonic velocity, hysteresis, magnetic field

DOI: 10.3233/JAE-2010-1262

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 3-4, pp. 1365-1372, 2010

Authors: Wang, Zhenxing | Yan, Peng | Geng, Yingsan | Yu, Li

Article Type: Research Article

Abstract: One disadvantage of traditional permanent magnetic actuators (PMA) in vacuum circuit breakers (VCB) is that it is difficult to improve the velocity characteristics so that the interruption capacity of VCBs will be constrained. The objective of this paper is to propose a method for controlling PMAs to enhance the velocity characteristics. In contrast to the traditional control method that adopts only one coil in an opening or closing operation, the new method adopts both coils in …the PMA simultaneously and controls the direction of the current in coils. Then a simulation model that involves coupled physical fields is constructed according to the new method. Moreover, the simulation results indicate that the initial velocity can be increased in the opening operation and the velocity characteristics in the closing operation can be optimized. In addition, the operating current can be reduced so that it is easy to control. Finally, experimental results validate the simulation results. Show more

Keywords: Permanent magnetic actuators, vacuum circuit breakers, coupled physics fields

DOI: 10.3233/JAE-2010-1263

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 3-4, pp. 1373-1381, 2010

Authors: Nowacki, J.P. | Alshits, V.I. | Radowicz, A.

Article Type: Research Article

Abstract: The coupled 2D electro-elastic fields are found in the piezoelectric sandwich structure (substrate-layer-substrate) of unrestricted anisotropy containing the straight-line source parallel to the interfaces. The general line source consists of the four coinciding sources: the line of forces, the charged line, the dislocation line and its electrostatic analogue. The obtained solution is presented in a form of convergent Fourier integral. The integrand is implicitly expressed in terms of the eigenvalues and the eigenvectors of the …generalized Stroh matrix. Determination of these eigenvalues and eigenvectors requires additional computing. Specific features of the found fields are analyzed. Show more

Keywords: Piezoelectricity, anisotropy, 1D inhomogeneity, line defect

DOI: 10.3233/JAE-2010-1264

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 3-4, pp. 1383-1390, 2010

Authors: Wang, Jian | Li, Yinghong | An, Zhiyong | Wang, Cheng | Hou, Shengli

Article Type: Research Article

Abstract: Shock waves in supersonic flows can be effectively controlled by gas discharge plasmas, and thermal mechanism has gained preliminary consensus in the literature. In the present paper, we try to validate the thermal mechanism of shock wave control by gas discharge plasmas experimentally. Surface dielectric barrier discharge (DBD) plasma and surface arc discharge plasma were selected as representatives of low-temperature cold plasmas with weak thermal effect and low-temperature thermal plasmas with strong thermal effect, …respectively. An oblique shock wave from a wedge was controlled by these two types of gas discharge plasmas respectively in a Mach 2.2 wind tunnel. Schlieren photography and gas pressure measurement results demonstrated that the cold DBD plasma had no obvious control effect on the shock wave, but the shock wave structure was distinctly changed by the hot arc discharge plasma. Under test condition of arc discharge power 1.3 kW, the start point of shock wave shifted upstream 4 mm, the shock wave angle decreased 8.6% and its strength weakened 8.8%. Therefore, we conclude that only the low-temperature thermal plasmas with substantial heat energy addition to the supersonic flow field have the control abilities on shock wave. This work will provide more evidence on the thermal mechanism of shock wave control by gas discharge plasmas. Show more

Keywords: Shock wave, dielectric barrier discharge (DBD), arc discharge

DOI: 10.3233/JAE-2010-1265

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 3-4, pp. 1391-1396, 2010

Authors: Ando, Yoshinori | Ito, Masaru | Murakami, Iwanori

Article Type: Research Article

Abstract: A magnetic gear doesn't have the noise, the vibration and the dust because a magnetic gear transmits power without contact. However, the transmission torque cannot be enlarged. For the current magnetic gear, the diameter of the gear and the centrifugal force grows larger when the transmission torque is increased. When the centrifugal force grows excessively, the possibility of the magnet dispersion increases. A cylindrical magnetic gear has prospects of improvement on these weak points of a …past magnetic gear. Therefore the purpose of this research is to develop the cylindrical magnetic gear experimental device. Show more

Keywords: Magnet gear, torque transmission, torque ratio

DOI: 10.3233/JAE-2010-1266

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 3-4, pp. 1397-1404, 2010