Nondestructive detection system of sheet metal by ultrasonic planar guided-wave and detection method thereof

Abstract

The invention provides a nondestructive detection system of sheet metal by ultrasonic planar guided-wave. An ultrasonic transceiver of the system is connected with an encoder and a sensor. The encoder and the sensor are connected with a controller. The sensor is coupled to a steel plate to be detected through machine oil used as a couplant. Electrical signal transmission process of the system is as follows: a computer inputs excitation parameters to control the ultrasonic transceiver to apply an excitation signal onto the sensor while positional information acquired by the encoder and an echo signal acquired by the sensor are transmitted to the computer through the ultrasonic transceiver. Meanwhile, the invention provides a nondestructive detection system of sheet metal by ultrasonic planar guided-wave and a detection method thereof. The invention has the following beneficial effect: by the characteristic that propagation distance of ultrasonic Lamb wave is long, detection range is large and large-area long-distance detection of a plate can be realized only from one detecting point, continuous acquisition of test data can be carried out, and fast effective large-area detection of a sheet metal structure can be achieved. The ultrasonic Lamb wave detection process is flexible and convenient. Quantitative assessment is achieved; detection efficiency is high; and it is easy to achieve automation.

Description

technical field [0001] The invention relates to the technical field of non-destructive testing of thin metal plates, in particular to a non-destructive testing system and a testing method for metal plates with ultrasonic plate guided waves. Background technique [0002] As a common structural form, metal sheet structure is widely used in petroleum industry, shipbuilding industry and other fields. During the long-term service, the metal sheet structure will be affected by factors such as the use environment, and different degrees of structural damage will occur. Therefore, the safety detection of such structures not only helps to prevent safety accidents, but also avoids unnecessary economic losses. [0003] At present, the non-destructive testing methods for sheet metal structures mainly include: magnetic flux leakage testing, ultrasonic C-scanning, penetration and acoustic emission testing, etc. Among them, although magnetic flux leakage detection and ultrasonic C-scan de...

AI Technical Summary

Problems solved by technology

The detection method has two disadvantages. One is that the modal conversion generated by the interaction between the Lamb wave and the defect is very complicated, and the conversion mode is not easy to accurately extract and analyze; the other is that the position of the sensor is fixed. This method is not applicable to the situation where the sensor is placed on the side, the detection process is not flexible, and the maneuverability is poor

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