International Journal of Applied Electromagnetics and Mechanics - Volume 52, issue 3-4

Authors: Han, Jinhui | Huang, Songling | Zhao, Wei | Wang, Shen

Article Type: Research Article

Abstract: Electromagnetic emission signal induced in fractured rocks has a wide frequency band, and the change in signal amplitude is very severe. In this paper, based on the analysis of the stress change at the crack tip, the stress excited electrical dipole (SEED) model had been established. Then the self-expanding destructive experiments were carried out by different rocks. The simulation results based on the model had been indicated that the intensity of the signal is closely related to the variation of the stress near the crack tip. The frequency of the signal is not only related to the mode of the …crack, but also the material properties. Show more

Keywords: Electromagnetic emission, fracture, rock, stress excited, electrical dipole

DOI: 10.3233/JAE-162182

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 52, no. 3-4, pp. 1023-1034, 2016

Authors: Shao, Shubao | Xu, Minglong | Zhang, Feng | Song, Siyang | Chen, Jie

Article Type: Research Article

Abstract: A piezo-driven antenna orientation stage is presented where two pairs of rhombic piezoelectric actuators (RPAs) are used to achieve the out-of-plane antenna motion, and the scanning range of this stage is maximized by maximizing the strokes of the RPA pairs. Two maximization strategies are implemented and compared. The first is based on an analytical model, and the second is based on a finite element (FE) model. The analytical model usually shows large errors because of the simplifications that must be made during structural analysis and because it ignores the electromechanical coupling characteristics of the piezo-stack. In contrast, the FE model …can provide much more accurate solutions by considering the piezo-stack and its electromechanical coupling characteristics. Then, the particle swarm optimization (PSO) method, which is independent of the mathematical models, is used to determine the optimal FE model parameters. In this way, more accurate optimal geometrical parameters are obtained for the rhombic amplifier. Finally, two specimens, which have different optimal geometrical parameters from the analytical and FE models, are fabricated and tested for comparison. The experimental results show that the optimization method based on the FE model is feasible, and is more accurate and efficient. Show more

Keywords: Rhombic piezoelectric actuator, finite element analysis, particle swarm optimization, maximization

DOI: 10.3233/JAE-162153

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 52, no. 3-4, pp. 1035-1043, 2016

Authors: Fujii, Akira | Adachi, Toshiki | Gotoh, Yuji

Article Type: Research Article

Abstract: In the inspection of the steel wall of the tank in the petrochemical plant etc., it is necessary to detect the opposite side defect from the surface of the steel wall. In this paper, the electromagnetic inspection method using alternating (ac) and static (dc) magnetic field is proposed. And, this method is investigated by verification experiment and 3-D nonlinear finite-element method (FEM) taking account of hysteresis (minor loop) and eddy current. It is shown that the detection of opposite side defect is possible by the differential permeability of minor loop of which the position on the hysteresis loop is affected …by the existence of defect. Show more

Keywords: 3-D nonlinear FEM, non-destructive inspection, opposite side defect in steel plate, alternating and static magnetic field, minor loop magnetism property

DOI: 10.3233/JAE-162185

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 52, no. 3-4, pp. 1045-1052, 2016

Authors: Gotoh, Yuji | Komori, Hiroyuki | Ueno, Jyunpei

Article Type: Research Article

Abstract: The development of the inspection technique of detecting the slack of the high tension bolt is desired. The permeability inside the side of the bolt head is changed since the bolt head is compressed by bolting a plate. Therefore, the evaluation of the slack of the bolt is possible by detecting the difference of the magnetic characteristics. In this paper, the inspection method for measuring the slack of the steel high-tension bolt of hexagon head using a small electromagnetic non-contacting sensor is proposed. The distribution of stress, flux density and eddy current density near the bolt head is estimated by …3-D nonlinear electromagnetic finite element method (FEM) analysis taking account of the electromagnetic property under various compressive stresses. The results showed that the non-destructive inspection of the slack of the high-tension bolts is possible by detecting the change of flux density in the side of the bolt head. Show more

Keywords: Slack of the high tension bolt, compressive stress, non-destructive inspection, 3-D stress FEM, 3-D nonlinear electromagnetic FEM, B-H curve

DOI: 10.3233/JAE-162222

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 52, no. 3-4, pp. 1053-1060, 2016

Authors: Zhang, Wenguang | Ma, Yakun | Li, Zhengwei

Article Type: Research Article

Abstract: During the process that neural probes are implanted, the insertion will cause acute injury of brain tissue and then trigger reactive responses, which may lead to degradation of the recording signals. In this paper, the process of neural probe's insertion into brain was simulated by developing a nonlinear finite element model. An element deletion method based on maximum shear stress criterion was utilized as the failure mechanism of brain tissue. It was found that as the wedge angle of the probe increases, the injury of brain tissue becomes larger. Besides, faster insertion speed leads to less tissue injury. The probe …stiffness, however, gives a negligible effect on tissue injury. The results are helpful to minimize the insertion trauma based on optimal design of insertion parameters and neural probe physical characteristics. Show more

Keywords: Neural probe, insertion process, finite element

DOI: 10.3233/JAE-162177

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 52, no. 3-4, pp. 1061-1067, 2016

Authors: Honmyo, Katsufumi | Kikuchi, Hiroaki

Article Type: Research Article

Abstract: To develop magnetic sensors operating at high temperatures, we evaluated the magnetic parameters of several soft magnetic materials. Although NiFe is a most competent candidate for a magnetic field sensor at room temperature, it is ineffective at higher temperature (above 400°C). On the other hand, Fe based alloy can be expected as a candidate material having a high permeability at higher temperatures due to high Curie temperature. Especially, FeSi steel is most expected to be utilized to a magnetic sensor operating at high temperatures.

Keywords: Permeability, inductance, Curie temperature, magnetic sensor, high temperature

DOI: 10.3233/JAE-162170

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 52, no. 3-4, pp. 1069-1073, 2016

Authors: Yanagiwara, Hiroki | Murakami, Takeshi | Kikuchi, Hiroaki

Article Type: Research Article

Abstract: We investigated the relationship between sensitization and magnetic characteristics of austenitic stainless steel with different composition. The saturation magnetization increased with increasing heat treatment time and the coercivity increases at first and then decreases for the specimens with higher carbon content. The changes in magnetic properties are not remarkable for the specimens with lower carbon content. The area where the chromium carbides formed yields chromium depletion zone and shows ferromagnetic properties. Chromium depletion zone induces martensitic transformation because the martensitic transformation temperature rises. The obtained results indicate that sensitization is detectable using magnetic measurement.

Keywords: Martensitic transformation, paramagnetic, ferromagnetic, nondestructive evaluation (NDE), sensitization, Cr depletion

DOI: 10.3233/JAE-162171

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 52, no. 3-4, pp. 1075-1080, 2016

Authors: Kosaka, Wataru | Oikawa, Shun-ichi | Chan, Poh Kam

Article Type: Research Article

Abstract: We have numerically solved the two-dimensional time-dependent Schrödinger equation for a charged particle in the presence of a non-uniform electric field E = E ≤(1- y / L_E ) e_y as well as a non-uniform magnetic field B = B ≤(1- y / L_B ) e_z. It is shown that such a non-uniformity of the electric field does not affect the time rate of the variance, or uncertainty, changes in position and momentum, while that of the magnetic field does.

Keywords: Schrödinger equation, uncertainty, non-uniform magnetic field, non-uniform electric field, quantum mechanical effect, expansion rate, GPU parallel computing

DOI: 10.3233/JAE-162208

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 52, no. 3-4, pp. 1081-1086, 2016

Authors: Fu, Xin | Xie, Shilin | Li, Jian | Zhu, Changchun | Zhang, Xinong

Article Type: Research Article

Abstract: The strain (or stress) responses of structures are generally of primary concern because they can provide an important reference to the assessment of structure failure modes as well recognized. The response surface method (RSM) is employed in strain response-based finite element model updating in the paper. The model updating procedures are outlined and the approach is then applied to a simply supported beam model. In addition, the traditional updating method (sensitivity-based method) is compared with the RSM method. The results show that response surface models can accurately reflect the relationships between design parameters and characteristic quantities and thus possesses better …strain response correction performance than the traditional method. Besides that, the RSM based model updating by modifying boundary conditions is conducted, which is difficult to achieve with the sensitivity-based method. The model updating based on measured data validates the effectiveness and accuracy of the present method. Show more

Keywords: Strain response, response surface method, model updating, optimization

DOI: 10.3233/JAE-162149

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 52, no. 3-4, pp. 1087-1097, 2016

Authors: Sun, Yanhua | Ye, Zhijian | Yang, Guangyou | Li, Donglin | Liu, Shiwei | Kang, Yihua | Gu, Min | Liu, Changde

Article Type: Research Article

Abstract: In this paper, pulsed electric flux leakage (PEFL), a new electromagnetic (EM) non-destructive testing (NDT) technique, is introduced. The inspection principle, which is to evaluate defects in metallic components carrying pulse current, was briefly described. Physical experiments with a prototype capacitive probe were carried out. Effects of through-hole diameter of the stainless specimen, surface-crack depth and sub-surface crack inspection were studied. The proof-of-concept results indicated that the PEFL testing method could be used to detect not only the surface defects but also the sub-surface defects, and of complete feasibility and the potential of great practical value as a supplement of …conventional NDT methods. Show more

Keywords: Electric field, coplanar capacitor, pulsed electric flux leakage, pulse current

DOI: 10.3233/JAE-162198

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 52, no. 3-4, pp. 1099-1106, 2016