High efficiency guided-wave magnetooptic Bragg cell modulator using nonuniform bias magnetic field

1997 ◽  
Vol 71 (25) ◽  
pp. 3715-3717 ◽  
Author(s):  
C. S. Tsai ◽  
Y. S. Lin ◽  
J. Su ◽  
S. R. Calciu
Keyword(s):  
Magnetic Field ◽  
High Efficiency ◽  
Guided Wave ◽  
Bias Magnetic Field

A flexural mode guided wave transducer for pipes based on magnetostrictive effect

2020 ◽  
Vol 64 (1-4) ◽  
pp. 335-342
Author(s):  
Yun Sun ◽  
Jiang Xu ◽  
Chaoyue Hu ◽  
Guang Chen ◽  
Yunfei Li
Keyword(s):  
Magnetic Field ◽  
Guided Waves ◽  
Permanent Magnets ◽  
Wave Structure ◽  
Guided Wave ◽  
Circumferential Direction ◽  
Bias Magnetic Field ◽  
Flexural Mode ◽  
Axial Crack ◽  
Wave Transducer

The flexural mode guided waves of pipes which are sensitive the axial crack and suitable for wave focused gain more attention recently. In this paper, a non-contact flexural mode guided wave transducer based on magnetostrictive effect is provided for pipes. Based on the magnetostrictive transduction principle and the wave structure of the flexural mode guided wave, the sensing method for generating and receiving the flexural mode guided waves based on magnetostrictive effect is obtained. According to the theoretical analysis, a non-contact magnetostrictive transducer for F (3, m) mode guided waves is given. Six permanent magnets which are evenly distributed in the circumferential direction of the pipe and arranged in opposite polarities are employed to provide the bias magnetic field in the circumferential direction. A solenoid coil is employed to induce the axial alternating magnetic field. The bias magnetic field distribution of the flexural mode guided wave in the pipeline is analyzed by the finite element simulation. The mode of the transduction guided wave in the pipe is verified by experiments based on the dispersion curves.

Analysis of the giant magnetostrictive actuator with strong bias magnetic field

2015 ◽  
Vol 394 ◽  
pp. 416-421 ◽  
Author(s):  
Guangming Xue ◽  
Zhongbo He ◽  
Dongwei Li ◽  
Zhaoshu Yang ◽  
Zhenglong Zhao
Keyword(s):  
Magnetic Field ◽  
Bias Magnetic Field ◽  
Magnetostrictive Actuator

Non-linear dynamics of the Villari effect in the presence of a non-homogeneous magnetic field

2018 ◽  
Vol 233 (4) ◽  
pp. 431-440
Author(s):  
Andrzej Rysak ◽  
Magdalena Gregorczyk
Keyword(s):  
Magnetic Field ◽  
Time Series ◽  
Hysteresis Loops ◽  
Bias Field ◽  
Homogeneous Magnetic Field ◽  
Operating Conditions ◽  
Bias Magnetic Field ◽  
Linear Dynamics ◽  
Non Linear ◽  
Magnetostrictive Devices

Investigations of systems with an active magnetostrictive element generally assume the presence of an external homogeneous bias magnetic field. This article, however, presents the results of a study investigating a bimorph magnetostrictive-aluminium beam vibrating in a non-homogeneous bias field. By comparing results obtained under different operating conditions of the system, the combined effect of the non-linear beam stress and the non-homogeneous external magnetic field on the dynamics of the Villari phenomenon is determined. The preliminary results prove that the application of non-linear magnetic fields to the magnetostrictive devices ensures the extension of energy harvesting bandwidth of these devices and can be used to improve their control possibilities. A study of time series and hysteresis loops provides more detailed information about the non-linear magnetization and dynamics of the system.

Permanent Magnet Heater for Special Applications

2015 ◽  
Vol 792 ◽  
pp. 476-481
Author(s):  
Michele Forzan ◽  
Fabrizio Dughiero
Keyword(s):  
Magnetic Field ◽  
Rare Earth ◽  
Induction Heating ◽  
Permanent Magnets ◽  
Lower Cost ◽  
High Efficiency ◽  
Mechanical Design ◽  
Fixed Position ◽  
Dc Magnetic Field ◽  
Research Activities

This paper presents a review of the research activities carried out at the Laboratory for Electroheat of Padova University (LEP) in the field of high efficiency through heating of aluminum workpieces. Induction heating obtained by rotating a billet in a DC magnetic field produced by superconductive coils was the first attempt to reach high electrical efficiency in mass heating of high conductive metals, like aluminum, copper and brass. More recently, the same concept has been applied by rotating rare earth permanent magnets around a metal billet kept in a fixed position. This technology appears much more promising because of lower cost of installation and a more robust mechanical design.

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