Handheld type knocking detector and detection method

Abstract

The invention relates to a handheld type knocking detector. The detector comprises a knocking hammer, a driving module, and a microprocessor control unit. The detector is characterized in that the knocking hammer comprises an electromagnetic coil, a ferromagnetic block, a metal frame, a metal sliding rod, a spring, and a knocking head; and the knocking head comprises a piezoelectric sensor and a hammer head. The invention also relates to a detection method. The method comprises the following steps of: sampling a standard test piece of a honeycomb composite material firstly, and collecting voltage waveforms of defect-free locations; amplifying a signal output by a piezoelectric sensor by carrying out amplification isolation, and converting a differential signal into a single-ended signal toobtain a smooth signal with good quality; obtaining a wave width W0 of the smooth signal as a debonding degree of the standard test piece; and detecting a to-be-tested piece to obtain a signal wave width W1 of the to-be-tested piece, and comparing W1 with W0, the greater the difference value, the stronger the degree of debonding, and the smaller the value, the better the quality. The handheld type knocking detector and the detection method have the advantages of being convenient and fast to detect and high in precision.

Description

technical field [0001] The invention relates to a hand-held knock detector. Background technique [0002] With the continuous development and innovation of aviation technology and composite material technology, honeycomb composite materials have been more and more widely used in the field of aviation industry. Due to the characteristics of the internal structure of honeycomb composite materials, defects such as delamination and debonding are prone to occur under some construction environments, non-design loads, and impacts of foreign objects. Aerospace devices must have extremely high precision and safety performance, so non-destructive testing of aerospace devices is required. [0003] Percussion testing is an important non-destructive testing method. For the defects of delamination and debonding of honeycomb composite materials, traditional percussion testing is that aircraft maintenance personnel often use tools similar to small hammers to tap honeycomb materials with ap...

AI Technical Summary

Problems solved by technology

[0005] From the perspective of percussion sensor sensitivity, the percussion sensors of some existing detection equipment all use piezoelectric ceramic sensors with single-layer piezoelectric sheets, or piezoelectric sensors with multi-layer stacked piezoelectric sheets have low sensitivity. Disadvantages, unable to detect weak signals, low detection resolution

[0006] From the perspective of the size of the sensor, if the traditional piezoelectric sensor wants to improve the sensitivity, it must increase the piezoelectric sheet, so that the volume becomes larger, the system space occupied becomes larger, the assembly is complicated, the integration is low, and the multi-point layout cannot be realized. Make the system trigger less reliable

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