Air Coupling Ultrasonic Testing System For Carbon Fiber Composites

Carbon fiber composite material has many excellent performance characteristics,which makes it more and more applications in aerospace and rail transportation,these two fields are closely related to the people's livelihood in China.The parts related to carbon fiber composite will inevitably produce different types of defects in the process of processing and use,which brings different degrees of hidden safety problems.Therefore,it is necessary to carry out related defect detection research.After analyzing several commonly used detection methods,this paper finally determines the ultrasonic nondestructive testing method to complete the defect detection of composite materials.This thesis focuses on the research of air-coupled ultrasonic defect detection technology for carbon fiber composites,which is a kind of defect detection technology for carbon fiber composites.At first,this article from the point of view of theoretical analysis of the ultrasonic attenuation characteristics of carbon fiber composite materials,and then on the basis of using COMSOL completed air coupling ultrasonic sound field simulation analysis,according to the distribution of sound field results validate the correctness of theoretical analysis and the feasibility of the detection scheme,and expounds the main problems and the cause of the ultrasonic attenuation,It provides important basis for hardware and software system design.Then,a set of hardware system based on ZYNQ7010 and upper computer software system based on QT5.13 are designed.Finally,a set of experimental detection system with high integration and good expansibility is provided.Then in view of the existing experimental equipment acquisition signal signal-to-noise ratio(SNR)of the contrast and the problem of large amount of data,continues to develop the ultrasonic signals collected in the signal noise,signal extraction and data compression algorithm of related research and analysis,finally identified by wavelet transform de-noising processing and compression perception of OMP algorithm of combining the way of ultrasonic signal processing,These two algorithms are integrated into the upper computer software system.Finally,a detection system integrated with the algorithm is used to carry out the defect detection experiment of carbon fiber composite materials,and the analysis of the experimental results proves that the system designed in this paper has certain feasibility.The work in this thesis provides important engineering ideas and references for ultrasonic scanning imaging of carbon fiber composites,and has certain practical value.