Power Amplifying Device for Nonlinear Electromagnetic Ultrasonic Excitation Signal

Abstract

The invention provides a power amplification device for a nonlinear electromagnetic ultrasonic excitation signal, and relates to the technical field of nonlinear electromagnetic ultrasonic nondestructive testing. The device includes: a function generator, a first DC bias circuit, a second DC bias circuit, a three-winding input transformer, a first AC-DC superposition circuit, a second AC-DC superposition circuit, and a first linear power amplification module circuit , a second linear power amplification module circuit, a third linear power amplification module circuit, a fourth linear power amplification module circuit, a high-voltage direct current power supply, a three-winding output transformer and an AC coupling circuit. The output signal of the device can not only drive the electromagnetic ultrasonic transducer to generate ultrasonic waves with sufficient loud power at the fundamental frequency, but also suppress the even harmonics in the driving signal and reduce the influence of the nonlinearity of the excitation circuit on the detection results .

Description

technical field [0001] The invention relates to the technical field of nonlinear electromagnetic ultrasonic nondestructive testing, in particular to a power amplification device for nonlinear electromagnetic ultrasonic excitation signals. Background technique [0002] At present, the nonlinear ultrasonic testing technology has unique advantages in the detection of micro-cracks, micro-defects, interfacial debonding, delamination and other defects in metal materials and structures, and it is also an important tool for the mechanical properties of metal materials and structures such as fatigue and creep. An effective technical means for early prediction of degradation is a non-destructive testing technology that is rapidly emerging in recent years. In the conventional nonlinear ultrasonic testing technology, when the piezoelectric transducer is used for nonlinear testing of metal materials and structures to be tested, a coupling agent is required between the transducer and the ...

AI Technical Summary

Problems solved by technology

When the conventional linear amplification method is used to realize the electromagnetic ultrasonic guided wave power amplification circuit, due to the nonlinearity of the components in the circuit, the high-order harmonic components of the output signal are always unavoidable, and the second-order harmonic components have a great influence on the nonlinear detection results. great influence

The second-order harmonic component caused by the output signal of the conventional linear power amplifier circuit has little effect on the results of linear ultrasonic testing, but for the results of nonlinear ultrasonic testing, the second-order harmonic component caused by the output signal of the excitation device will be related to the material and the defect itself. The superposition of the second-order harmonics in the nonlinear ultrasonic signal caused by the second-order harmonics leads to misjudgment of the detection results of the ultrasonic nonlinear coefficients based on the second-harmonic amplitude

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