Method for detecting debonding defects of composite material glue bonding structure by using terahertz time-domain spectroscopy

Abstract

The invention discloses a method for detecting debonding defects of a composite material glue bonding structure by using terahertz time-domain spectroscopy. A glue bonding structure sample is prepared; a terahertz time-domain spectroscopy system is used for testing the glue bonding structure sample; a time domain signal of a bonding part of the glue bonding structure sample is acquired; the time domain signal is transformed into a frequency domain signal; two-dimensional scanning is performed on the glue bonding structure sample under a reflection mode of the terahertz time-domain spectroscopysystem to respectively obtain a three-dimensional time domain data matrix and a three-dimensional frequency domain data matrix; time axis data of the terahertz three-dimensional time domain data matrix is used for conducting imaging on the glue bonding structure sample; spectrum axis data of the three-dimensional frequency domain data matrix is used for conducting imaging on the glue bonding structure sample; the debonding defects of the glue bonding structure sample are manually identified according to the imaging results. According to the method, a to-be-tested sample is not damaged, the detection adopts a non-contact manner, and there is no need to apply other auxiliary substances on the surface of a composite material during the detection process, so that pollution and damage to the sample are avoided.

Description

technical field [0001] The invention relates to a method for detecting debonding defects of a composite material glued structure by terahertz time-domain spectroscopy. Background technique [0002] The bonding structure of composite materials has many advantages in engineering applications. Bonding technology is an increasingly widely used technology in modern industries including the defense industry, including between metal materials, metal materials and non-metal materials. Bonding of various materials between and non-metallic materials. Among them, the composite material sandwich structure is a laminated composite material. The panel and the core material are connected by adhesive bonding. It has the advantages of high strength, small weight, and low cost. It is widely used in aviation, radar, automobiles, and construction. , wind power and other fields. The influence of process conditions and environment during the bonding process can easily cause debonding defects on...

AI Technical Summary

Problems solved by technology

The influence of process conditions and environment during the bonding process can easily cause debonding defects on the bonding surface of the sandwich structure, and various factors such as fatigue, aging, and corrosion during the implementation process can also easily cause weak bonding or debonding defects, which greatly reduces Component performance, affecting the reliability of composite materials

[0003] In the non-destructive testing technology of the bonding condition of the interface of the bonded structure, the commonly used ray testing method is not sensitive to the delamination defects in the composite material, and it is difficult to find the defects in the direction perpendicular to the ray; the ultrasonic testing method is contact testing, and the speed is slow. , the detection period is long; the infrared detection method detects the bonded structure, which has requirements on the thickness of the panel and the thermal conductivity of the material

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