An integrated pulsed ultrasound-acoustic emission transducer for inspection of composite materials

Abstract

The invention relates to an integrated pulsed ultrasound-acoustic emission transducer for detecting composite materials. Including piezoelectric sensing element, transducer housing, damping back block, time delay block, electrode, connecting seat, cover and locking ring. The broadband piezoelectric crystal is used as the ultrasonic excitation and acoustic emission signal reception, which belongs to the integrated ultrasonic-acoustic emission transducer, small in size, good in time-domain pulse characteristics, high in detection sensitivity and resolution, and very regular in ultrasonic-acoustic emission signals. Clear, qualitative and quantitative accuracy of defect detection, very good applicability, can be used for manual scanning detection and automatic scanning detection and defect imaging analysis of different composite material parts, significantly improved the composite material ultrasonic detection resolution and surface detection blind area, greatly improved The ability to detect defects in composite materials has been improved, the detection thickness can reach 50mm, the detection sensitivity can reach Ф3mm, 45mm deep defects, and the frequency selection range is 1‑7.5MHz.

Description

technical field [0001] The invention belongs to the non-destructive testing technology, and relates to an integrated pulse ultrasonic device for detecting composite materials used in the non-destructive testing of composite materials and metal material structures in the fields of aviation, aerospace, weapons, ships, metallurgy, steel, transportation, construction, etc. Acoustic emission transducer. Background technique [0002] Ultrasound is an important method widely used in quantitative non-destructive testing of various materials and their structural defects. It has been widely used in aerospace, weapons, electronics, ships, metallurgy, petrochemical oil, transportation, construction and other fields, especially in composite materials At present, 80% of composite material structures are tested by ultrasonic testing. At present, the ultrasonic testing methods for composite materials mainly include reflection method and penetration method. Using external ultrasonic pulse s...

AI Technical Summary

Problems solved by technology

At present, the ultrasonic testing methods for composite materials mainly include reflection method and penetration method. Using external ultrasonic pulse sound source, the reflection / transmission sound wave behavior formed in the tested composite material is used to detect and discriminate defects. The main disadvantages are : (1) It is very sensitive to the orientation of the defect. As the angle between the orientation of the defect and the propagation direction of the incident sound wave increases, the detection ability of the defect will decrease significantly, which will easily cause missed detection; (2) The sound wave attenuation is severe, and it is difficult to Realize non-destructive testing of materials with severe acoustic attenuation such as large-thickness composite materials and porous composite materials

Its main disadvantages are (1) the volume is too large and synchronization is difficult; (2) the geometric scanning blind area is large; (3) the time-domain pulse characteristics of the transducer are poor; (4) the resolution and detection sensitivity are low, and the detection signal law is complicated , the qualitative and quantitative defects are difficult

Images