Experimental study on rebar stress measurement based on force-magnetic coupling under excited magnetic field. (15th February 2022)

• Record Type: Journal Article
• Authors: Tong, Kai; Zhou, Jianting; Zhao, Ruiqiang; Hu, Wenxue; Qu, Yinghao; Cheng, Chongshen
• Is Part Of: Measurement. Volume 189(2022)
• Publication Date: 2022-02-15
• Subjects: Excitation magnetic field -- Rebar stress -- Force-magnetic coupling -- Stress detection -- Elastic phase; Weights and measures -- Periodicals; Measurement -- Periodicals; Measurement; Weights and measures; Periodicals; 530.8
• DOI: 10.1016/j.measurement.2021.110620
• Languages: English
• ISSNs: 0263-2241

Abstract

Highlights: The weak magnetic excitation method can reduce the differentiation of the magnetic signal variation in tensile processes of rebars with different initial residual states. The parametric AW, which can quantify the stress state of the rebar, was proposed and a linear relationship between AW and the tensile load T in the elastic stage was obtained. An expression of the rebar stress state is obtained, with a deviation rate of under 15% between the calculated and actual stress values. The lift-off value has an impact on the measured sensitivity, and reducing the lift-off value can improve the effectiveness of the stress state measurement. Abstract: This paper used weak magnetic detection technology for nondestructive testing of rebar stresses. An applied excitation magnetic field was used to reduce the effect of different initial residual states of the rebar and to strengthen the force-magnetic coupling effect of the static tension process. Five sets of rebar samples were prepared, and magnetic field excitation with different magnitudes was applied. The tangential component of magnetic induction By is analyzed and the 'magnetic signal curve fluctuation parameter' AW is introduced. The results showed that the consistent variation pattern AW -T curves indicated magnetic field excitation could reduce the magnetic differences in various rebars tensile processes. When the excitation magnetic field strength exceeds the geomagnetic field, the AW -T curve in the elastic phase decreases linearly. By extracting the magnetic signals, the stress state in the elastic phase of the rebar is calculated by substituting for the formula, and the control error is within 15%.