Affiliations: School of Civil Engineering, Xi'an University of Architecture and Technology, Xi'an, Shaanxi, China
Correspondence:
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Corresponding author: Shuchun Yi, School of Civil Engineering, Xi'an University of Architecture and Technology, No. 13, Yanta Road, Xi'an, Shaanxi 710055, China. Tel.: +86 18066611812; Fax: +86 29 82205864; E-mail:yscone@live.xauat.edu.cn
Abstract: Metal magnetic memory (MMM) is an effective magnetic
method in evaluating stress concentration and early damage. To get the
normal component of surface spontaneous magnetic signal of the specimen
under different loads, three-point flexural test and four-point flexural
test of Q235B steel specimens were carried out. Von Mises yield criterion
was employed to calculate equivalent stress. The results show that the
magnetic signal curve has a strong regularity during loading stage. For a
three-point bending specimen, the magnetic signal curve presents ``triangle''
distribution. For a four-point bending specimen, the magnetic signal curve
of the flange and web present ``trapezoid'' and ``saddle'' distribution,
respectively. The symmetry of magnetic signal curve can be used to determine
whether a specimen is under eccentric compression. The main tendency and
local extrema of equivalent stress are coinciding with that of magnetic
signal. A reasonable qualitative correlation is found between the
distribution of equivalent stress and magnetic signal.
Keywords: Metal magnetic memory (MMM), bending test, equivalent stress, von Mises yield criterion, qualitative correlation
