Affiliations: [a] School of Mechanical Engineering, Hubei University of
Technology, Wuhan, 430068, China
Correspondence:
[*]
Corresponding author: Xiaochun Song, School of mechanical
engineering of Hubei University of Technology, Wuhan, 430068, China. Tel.: +86
27 88027375; Fax: +86 27 88032313; E-mail: songxc@mail.hbut.edu.cn
Abstract: The uniform and steady bias magnetic field is the key to improvement
of the transduction efficiency for the magnetostrictive guided-wave transducer.
To optimize the magnetic circuit of the magnetostrictive transducer and obtain
the best detection effects, the method to measure the homogeneity of magnetic
flux density by sample standard deviation was studied. And the effects of such
parameters as the thickness of the left and right enclosed magnetic conductor
shell, the thickness of the outside round shell of magnetic conductor, the
distance between the bias magnetic exciting coil and the pipe's outer wall on
the homogeneity of the excited bias magnetic field were analyzed
quantitatively, both finite element simulation and experimental analysis were
conducted to study the effects of different magnetic circuit design schemes on
the excited bias magnetic field's homogeneity. The simulation results indicate
that the homogeneity of the magnetic field is obviously improved with the above
three parameters increasing, and the relatively uniform magnetic field can be
obtained when the above parameters are all taken the maximum value of 20~mm.
Keywords: Bias magnetic field, homogeneity, standard deviation, magnetostriction, guided wave
