Session: NDE-03-01 NDE Reliability - Modeling and Experimental Analysis

Paper Number: 106142

106142 - Modeling and Experimental Analysis of Electromagnetic Ultrasonic Testing Considering Effect of Rough Surface Layer 

Electromagnetic ultrasonic testing has advantages of non-contact, no coupling, which is suitable for regular testing or long-term monitoring of pressure equipment with high temperature, coating. The inner and outer walls of pressure vessel or pipeline in long-term service are easy to form rough surface due to corrosion, soil alkaline and other factors. It leads to the increase of background noise and the change of sound field energy for electromagnetic ultrasonic testing and restricts the improvement of detection accuracy. In this paper, a numerical model of electromagnetic ultrasonic testing model with random rough surface is established based on the constitutive equation of Lorentz and magnetostriction forces for the ferromagnetic material. The distribution of eddy current near the surface and the variation characteristics of Lorentz and magnetostrictive force density in excitation or receiving process of electromagnetic ultrasonic testing are analyzed. The characteristics of energy conversion of multi physical coupling fields under effect of rough front surface, and the influence of rough back surface on energy attenuation in sound wave propagation are clarified. Then, the variation law of wall thickness measurement accuracy for electromagnetic ultrasonic testing under rough surface was obtained by simulation and experiment. The results show that more interference sound waves are caused by rough front surface and the attenuation of signal-to-noise ratio is more significant comparing to rough back surface. When the roughness of front or back surface is within 120μm, the accuracy in a single measurement is within 0.06mm, and better wall thickness accuracy can be obtained by means of multiple measurements. When the surface roughness is greater than 120μm, the measurement error is greater than 0.1mm. Therefore, when the surface of pressure equipment is in good condition, the non-grinding high-precision thickness measurement process for electromagnetic ultrasonic testing can be realized. When the surface roughness is large, local grinding can significantly improve the detection accuracy.

Presenting Author: Zhe Wang Hefei General Machinery Research Institute Co., Ltd

Presenting Author Biography: Zhe Wang was born in Anhui Province, China, in 1991. He received his BSc and PhD from School of Mechanical Science & Engineering at Huazhong University of Science and Technology (HUST), China, in 2013 and 2019, respectively. Immediately after graduation, he joined the Hefei General Machinery Research Institute Co., Ltd as an assistant research fellow. His current research interests include nondestructive testing technology research and instrumentation development, such as piezoelectric/electromagnetic ultrasonic waves, electromagnetic and air-coupled acoustic resonance detection.

Authors:

Zhe Wang Hefei General Machinery Research Institute Co., Ltd
Zhichao Fan Hefei General Machinery Research Institute Co., Ltd
Xuedong Chen Hefei General Machinery Research Institute Co., Ltd
Jingwei Cheng Hefei General Machinery Research Institute Co., Ltd
Haibin Wang Hefei General Machinery Research Institute Co., Ltd
Yangguang Bu Hefei General Machinery Research Institute Co., Ltd