A Nonlinear Method for Characterizing Discrete Defects in Thick Multilayer Composites

Applied Sciences

Xiang Zeng¹  Xiaojun Zhou²  Chenlong Yang²  Guoyang Teng² 

[1] CRRC Zhuzhou Institute Co., Ltd., Zhuzhou 412001, China;The State Key Lab of Fluid Power and Mechatronic Systems, Zhejiang University, Hangzhou 310027, China;

关键词: thick multilayer composites;    discrete defects;    ultrasonic pulse echo;    nondestructive testing (NDT);    recurrence plot (RP);    recurrence quantification analysis (RQA);    statistical results;    chaotic behavior;   

DOI  :  10.3390/app9061183

来源: DOAJ

【 摘 要 】

Discrete defects in thick composites are difficult to detect for the small size and the structure noise that appears in multilayer composites. In this paper, a nonlinear method, called recurrence analysis, has been used for characterizing discrete defects in thick section Carbon Fiber Reinforced Polymer (CFRP) with complex lay-up. A 10 mm thick CFRP specimen with nearly zero porosity was selected, and blind holes with different diameters were artificially constructed in the specimen. The second half of the backscattered signal was analyzed by recurrence analysis for areas with or without a defect. The recurrence plot (RP) visualized the chaotic behavior of the ultrasonic pulse, and the statistical results of recurrence quantification analysis (RQA) characterized the instability of the signal and the effect of defects. The results show that the RQA variable differences are related to the size of blind holes, which give a probable detection of discrete geometric changes in thick multilayer composites.

【 授权许可】

Unknown