Elastic constant measuring method based on array magnet electromagnetic ultrasonic

Abstract

The invention relates to an elastic constant measuring method based on array magnet electromagnetic ultrasonic. The method comprises the steps of: designing and manufacturing a planar Halbach magnet array, and designing flexible printed coils with different structures based on the characteristics of the magnet array; integrating and assembling array magnet electromagnetic ultrasonic; and finally,measuring longitudinal wave and transverse wave echo sounds at the measured point by utilizing array magnet electromagnetic ultrasonic, and completing calculation of the elastic constant of the material. The method solves the problems of measurement efficiency and precision of the elastic constant of the material. A planar Halbach magnet array is innovatively designed, a vertical magnetic field and a horizontal magnetic field are obtained, and the magnetic field intensity is improved; the integrated structure of the flexible printed coil is optimized, and a sound time signal with a high signal-to-noise ratio is obtained; and meanwhile, transverse waves and longitudinal waves are excited, sound time signals with high signal-to-noise ratio are obtained, the spatial measurement resolution isimproved, and the requirement for rapid lossless accurate measurement of the elastic constant facing the manufacturing site environment can be met.

Description

technical field [0001] The invention belongs to the field of non-destructive testing, in particular to an elastic constant measurement method based on array magnet electromagnetic ultrasound. Background technique [0002] The elastic constant is one of the important performance parameters of engineering materials and the basis for evaluating the elasticity of solids. The traditional measurement method is to apply an external load, record the corresponding strain, and calculate the elastic constant according to Hooke's law. However, this method has a long measurement cycle, and the sticking of the strain gauge seriously affects the measurement accuracy of the elastic constant. Other measurement methods, such as X-ray diffraction method, Moire interferometry, etc., have a complicated measurement process. The ultrasonic method can realize the non-destructive and rapid measurement of elastic constants only by measuring the longitudinal wave and shear wave velocity, and has the...

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Problems solved by technology

[0004] In 2017, Zhan Yu and others disclosed a non-destructive testing method and equipment based on laser ultrasonic elastic constants in the invention patent CN201711035304.1. In this method, the pulsed laser is applied to the excitation point of the surface to be tested to generate ultrasonic waves, which can simultaneously generate Longitudinal wave, transverse longitudinal wave and surface wave, however, the method is expensive and the measurement process is complicated

In 2018, Yang Lijian and others disclosed an electromagnetic ultrasonic elastic modulus measurement transducer structure in the invention patent CN201810331216.4. This structure uses a permanent magnet to generate a bias magnetic field. Ultrasonic waves are generated near the surface, but the measurement structure can only generate one waveform, and the device is bulky and the measurement spatial resolution is low

[0005] However, none of the above mentions a method for measuring elastic constants based on array magnet electromagnetic ultrasound

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