Signal acquiring method for ultrasonic reflecting transmitting parallel detection of sandwich structure

Abstract

The invention belongs to the technical fields of aerospace manufacturing, traffic, building, electronic engineering and nondestructive detection, and relates to a signal acquiring method for ultrasonic reflecting transmitting parallel detection of a sandwich structure. The device for acquiring a detecting signal comprises a transmitting and receiving energy converter, a receiving energy converter,an ultrasonic emitting unit, a door selection unit, a reflecting signal handling unit, a time delay unit, a transmittance signal handling unit, a synchronizing unit and a data acquiring unit. According to the method, an ultrasonic signal in the single scanning process of the detected composite sandwich structure is preprocessed, collected and recorded, and the ultrasonic signal can be synchronously applicable to ultrasonic reflecting and transmittance scanning imaging; the detection costs a little time; the detection efficiency is high; the detection cost is obviously decreased; a high-pressure ultrasonic pulse exciting original signal is not directly loaded to the input stage in the preprocessing, so that a primary amplifier of a preprocessing device is prevented from blockage and damage, and as a result, the reliability and the accuracy of the detection result can be improved.

Description

technical field [0001] The invention belongs to the technical fields of aerospace manufacturing, transportation, construction, electronic engineering and non-destructive testing, and relates to a signal acquisition method for parallel detection of ultrasonic reflection and transmission of a sandwich structure. Background technique [0002] At present, ultrasonic automatic scanning imaging detection is a very important non-destructive testing method used in sandwich structures. One method is automatic scanning imaging detection using ultrasonic penetration method, using one transducer to emit ultrasonic signals, and the other transducer to receive Ultrasonic signal, the two transducers are respectively located at the two sides of the detected part, it is necessary to pre-process and collect and record the ultrasonic signal received by the receiving transducer during the scanning process, so as to be used for automatic scanning and imaging by ultrasonic penetration method, so a...

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Problems solved by technology

[0002] At present, ultrasonic automatic scanning imaging detection is a very important non-destructive testing method used in sandwich structures. One method is automatic scanning imaging detection using ultrasonic penetration method, using one transducer to emit ultrasonic signals, and the other transducer to receive Ultrasonic signal, the two transducers are respectively located at the two sides of the detected part, it is necessary to pre-process and collect and record the ultrasonic signal received by the receiving transducer during the scanning process, so as to be used for automatic scanning and imaging by ultrasonic penetration method, so as to realize The main disadvantage of the ultrasonic penetration method of the tested part is that when a defect is detected, it is necessary to use the ultrasonic reflection method to scan, scan the tested part again, and analyze the detection signal received by the transducer during the scanning process in real time. Pre-processing and acquisition records are used for ultrasonic scanning imaging to determine the position of the detected defect in the sandwich structure. The ultrasonic scanning imaging detection method based on this signal acquisition and recording is time-consuming and inefficient. high cost

Another method is to use the ultrasonic reflection method to automatically scan and image detection. A transducer is used to both transmit and receive ultrasonic signals. The ultrasonic signal received by the transducer is pre-processed and collected and recorded, and its main disadvantages are: 1) It is necessary to scan both sides of the sandwich structure to be tested to realize the detection of the sandwich structure to be tested. For this reason, it is necessary to The detection signals received by the transducer during the two scanning detection processes are pre-processed and collected and recorded before they can be used for ultrasonic scanning imaging detection. Based on this signal acquisition method, the detection is also time-consuming, low in efficiency, and high in detection cost; 2 ) In the detection of ultrasonic reflection method, since the original signal excited by the high-voltage ultrasonic pulse is usually directly loaded on the input stage of the pre-processing, it is easy to cause the first-stage amplifier of the pre-processor to be blocked or even damaged, and the original signal excited by the high-voltage ultrasonic pulse is harmful to the Weak detection signals are prone to interference, which will affect the quality of detection imaging and the reliability and accuracy of detection results

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