“Ultrasonic methods for structural health monitoring of composite objects” Doctoral Thesis

Author, institution: Vykintas Samaitis, Kaunas University of Technology

Science area, field: Technology Sciences, Electrical and Electronics Engineering – 01T

The Doctoral Dissertation is available at the library of Kaunas University of Technology (K. Donelaičio St. 20, Kaunas)

Scientific Supervisor: Prof. Dr. Liudas MAŽEIKA (Kaunas University of Technology, Technological Sciences, Electrical and Electronics Engineering – 01T)

Dissertation defence board of Electrical and Electronics Engineering science field:
Prof. Dr. Habil. Arūnas LUKOŠEVIČIUS (Kaunas University of Technology, Technological Sciences, Electrical and Electronics Engineering – 01T) – chairman;
Prof. Dr. Habil. Genadijus KULVIETIS (Vilnius Gediminas Technical University, Technological Sciences, Mechanical Engineering – 09T, Informatics Engineering – 07T);
Assoc. Prof. Dr. Alberto RODRIGUEZ MARTINEZ (Miguel Hernandez University of Elche, Technological Sciences, Electrical and Electronics Engineering – 01T);
Assoc. Prof. Dr. Reimondas ŠLITERIS (Kaunas University of Technology, Technological Sciences, Electrical and Electronics Engineering – 01T);
Prof. Dr. Algimantas VALINEVIČIUS (Kaunas University of Technology, Technological Sciences, Electrical and Electronics Engineering – 01T).

Annotation:

Knowing the integrity of complex in-service structures on a continuous real-time basis is very important objective for manufacturers, end-users and maintenance teams. The use of ultrasonic guided wave based structural health monitoring systems, enables partially to satisfy this demand. However, the complicated behaviour of guided waves introduces many challenges in developing non-destructive inspection techniques. The objective of the thesis was to develop ultrasonic guided wave methods for structural health monitoring of plate-like composite structures, enabling the feature extraction of detected damage, and techniques for validation of the monitoring system.
In this thesis, the set of novel ultrasonic signal analysis and interpretation methods, which are mandatory in order to properly analyse the complex behaviour of guided waves, to extract the features of detected damage and to validate the monitoring system, were proposed. These methods aim to solve the key problems in the field of guided wave structural health monitoring. The methods proposed in this research creates a framework for the guided wave based structural health monitoring system, that can predict the complex mechanism of guided wave generation; analyse multi-modal propagation; decompose guided wave signals captured on plate-like anisotropic structures; detect and describe the delamination type defects and validate the correctness of the inspection system upon installation to an in-service structure.