International Journal of Applied Electromagnetics and Mechanics - Volume 45, issue 1-4

Authors: Zeng, Zhiwei | Li, Yansong | Huang, Lin | Luo, Minfang

Article Type: Research Article

Abstract: Pulsed eddy current (PEC) testing has attracted researchers' interest because the pulsed excitation comprises a broad band of frequencies and the response signal provides more information about defect than traditional eddy current testing. Various features have been extracted from PEC signal for defect characterization. In this paper, we extract frequency-domain features and propose defect characterization scheme for identifying defect's location, radius, and height.

Keywords: Pulsed eddy current testing, defect characterization, feature

DOI: 10.3233/JAE-141885

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 45, no. 1-4, pp. 621-625, 2014

Authors: Oka, Koichi | Okazaki, Tomohiro | Morimitsu, Toshiyuki

Article Type: Research Article

Abstract: This paper describes 2 types of 2 DOF magnetic suspension systems which suspend two iron balls or an iron stick type object. Both suspension system controls 2 DOF of suspended object(s). The magnetic suspension forces are controlled by a generator of magnetomotive force. This suspension system must control two degrees of freedom without mechanical contacts. In iron stick suspension system, a vertical displacement and a horizontal rotation of the object should be controlled. This paper proves …the feasibility of these noncontact suspension systems. A theoretical analysis will be done on the model of these suspension systems and numerical simulations carried out for confirmation of performances. Show more

Keywords: Magnetic suspension system, simultanious 2 DOF motion control, permanent magnet

DOI: 10.3233/JAE-141886

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 45, no. 1-4, pp. 627-632, 2014

Authors: Lepage, Benoit

Article Type: Research Article

Abstract: Cross-wound eddy current sensors have been used for years in the non-destructive testing industry for surface detection of cracks on steel components. The conventional sensor, which is a three dimensional transmit-receive structure comprising two orthogonal coils, can't be directly translated to a flat winding suitable for printed circuit board (PCB) manufacturing. This paper describes a method that makes it possible, through the use of finite element modeling (FEM), to reproduce the cross wound sensor …response on a flexible printed circuit board. As a second step, an innovative compact PCB made cross-wound eddy current array (ECA) structure is presented and demonstrated experimentally. Show more

Keywords: Eddy current array, cross-wound, weld inspection, flexible PCB, probe

DOI: 10.3233/JAE-141887

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 45, no. 1-4, pp. 633-638, 2014

Authors: Jankowski, Piotr | Mindykowski, Janusz | Woloszyn, Miroslaw

Article Type: Research Article

Abstract: This paper presents the concept of determining the optimum frequency of coil supply in inductive-dynamic drive. As a criterion to obtain the sought frequency, the smallest value of reduced stress in the disc was assumed while maintaining the desired dynamics. The disc stress is determined on the basis of solution of vibrating thin plate equation. Magnetic pressure acting on the disc is obtained from a hybrid circumferentially-field model (CI-FI).

Keywords: Actuator, disc, magneto-elasticity, stress analysis

DOI: 10.3233/JAE-141888

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 45, no. 1-4, pp. 639-647, 2014

Authors: Jankowski, Piotr | Woloszyn, Miroslaw

Article Type: Research Article

Abstract: This paper presents the proposal of the hybrid circumferential-field model of an electrodynamic actuator. The field model uses the inductor current as the input data which is obtained from the circumferential model or experimentally. The field model implemented using the FLUX program makes it possible to easily determine the pressure distribution acting on the disc. The results have been verified experimentally.

Keywords: Thomson effect, actuator, drive, acceleration

DOI: 10.3233/JAE-141889

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 45, no. 1-4, pp. 649-657, 2014

Authors: Oyamada, Toshiyuki | Masuda, Hideaki | Ikari, Kazuki | Sawada, Tatsuo

Article Type: Research Article

Abstract: Magnetic fluid tuned liquid column damper (MF-TLCD) is a new semiactive damper. This device can exhibit high damping effect by tuning its natural frequency to the excitation frequency. In this study, the vibration characteristics of a magnetic fluid under a static magnetic field were investigated by linear analysis and experiment with single-degree-of-freedom oscillation. Moreover, MF-TLCD was installed within a structure and oscillated in double-degrees-of-freedom. It was confirmed that MF-TLCD could achieve high …performance compared with the conventional TLCD by controlling the magnetic field. Show more

Keywords: Magnetic fluid, tuned liquid column damper, natural frequency, vibration control

DOI: 10.3233/JAE-141890

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 45, no. 1-4, pp. 659-665, 2014

Authors: Fujita, Y. | Isnikurniawan, A. | Tanimoto, S. | Sawada, T.

Article Type: Research Article

Abstract: An experimental study in ultrasonic propagation characteristics of a magnetic fluid under AC magnetic fields was conducted. Sound velocities in a magnetic fluid increased with elapsed time of the AC magnetic fields. Moreover, rapid decreases in sound velocities in a magnetic fluid were observed when the AC magnetic fields were stopped. These results were similar to those for DC magnetic fields. Dependence of frequencies and magnitudes of AC magnetic fields on sound velocities in a magnetic …fluid was observed. Moreover, anisotropy was found in each frequency of the AC magnetic fields. Show more

Keywords: Magnetic fluid, ultrasonic, AC magnetic field, anisotropy

DOI: 10.3233/JAE-141891

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 45, no. 1-4, pp. 667-673, 2014

Authors: Ishiyama, Takayoshi | Kaneko, Shunsuke | Takemoto, Shin-ichiro | Sawada, Tatsuo

Article Type: Research Article

Abstract: This study investigates the behavior of two-layer sloshing using a magnetic fluid and silicone oil. To obtain basic relations, a linear theory is employed. After obtaining those relations, theoretical values of free-surface displacement, resonant frequency, and resonant pressure amplitude are compared with experimental results. Experimental data are obtained using a laser sensor and four pressure transducers. Free-surface displacement is measured by the laser sensor. Resonant frequency is measured by both the laser sensor and …pressure transducers. Resonant pressure amplitude is recorded by the pressure transducers. The results demonstrate that the theory employed in this study is effective as a first estimation of two-layer sloshing. However, to describe the behavior of a two-layer magnetic fluid sloshing more precisely, a nonlinear analysis that considers magnetic force is necessary. Show more

Keywords: Two-layer sloshing, magnetic fluid, linear theory analysis

DOI: 10.3233/JAE-141892

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 45, no. 1-4, pp. 675-682, 2014

Authors: Isnikurniawan, Ahmad | Ohba, Hiromichi | Kaneko, Hiro | Yoshizawa, Ryo | Sawada, Tatsuo

Article Type: Research Article

Abstract: This study is an investigation on the effect of a chamfered orifice inlet on magnetorheological (MR) fluid subjected to shock loading. Three different orifices (without chamfer, chamfered at 60°, and chamfered at 120° on the inlet area) are used. MR fluid is subjected to shock loading, and a magnetic field is generated on the orifice area. Experiments are conducted by measuring piston displacement and damping force. Piston velocity is calculated from the piston displacement data. The …results indicate that a chamfered orifice inlet affects the piston stroke, piston velocity, and damping force. The characteristics of piston velocity between the orifice without chamfer and the chamfered orifices are different. The post-peak decrease in piston velocity in the chamfered orifices is more refined than that in the orifice without chamfer. However, the chamfered shape in the orifice inlet reduces the shock loading performance of MR fluid. Show more

Keywords: Magnetorheological fluid, magnetic field, chamfered orifice, shock loading

DOI: 10.3233/JAE-141893

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 45, no. 1-4, pp. 683-688, 2014

Authors: An, Siguang | Yang, Shiyou | Wu, Xiushan

Article Type: Research Article

Abstract: An improved vector cross-entropy (CE) method is proposed to provide a potential candidate for solving multi-objective inverse problems with a large number of variables. To balance the exploitation and exploration searches, the whole iterative process is divided into two phases: diversification and intensification phases. Different parameter evolutionary mechanisms of the probability density functions (pdfs) are proposed for different phases. To speed up the convergence rate, a dynamic evolutionary mechanism is proposed. To …enhance the diversity of the sampling points, a mutation manipulation is introduced. The ZDT test functions and a high frequency inverse problem are used as the case studies to testify the effectiveness and efficiency of the proposed method. Show more

Keywords: Cross-entropy method, inverse problem, multi-objective, evolutionary algorithm

DOI: 10.3233/JAE-141894

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 45, no. 1-4, pp. 689-695, 2014