An investigation into the way in which longitudinal and flexural waves interact with corrosion-like damage

• Ano de defesa: 2019
• Autor(a) principal: Gonsalez-Bueno, Camila Gianini
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Universidade Estadual Paulista (Unesp)
• Palavras-chave em Português: Longitudinal waves; Flexural waves; Piezoelectric elements; Structural health monitoring; Corrosion; Ondas longitudinais; Ondas flexurais; Elementos piezelétricos; Monitoramento da integridade estrutural; Corrosão
• Link de acesso: http://hdl.handle.net/11449/181311

The guarantee of security in transport vehicles, buildings, bridges and critical structures is extremely important for people and the environment. Therefore, in the last decades, several Structural Health Monitoring (SHM) techniques have been proposed and developed for many areas. One technique to detect corrosion could be the use of guided waves. Considering one wave travelling in a structure and impinging on a discontinuity (damage), this wave will interact with this discontinuity and will be scattered. Thus wave motion in structures may be a powerful way to indicate the presence of damage in a structure. This work aims to investigate wave propagation in a thin Euler-Bernoulli infinite beam, and the way in which these waves interact with simulated corrosion damage (symmetric and asymmetric). The studies show the importance to know the behavior of waves before chose main frequencies to used for a SHM system. Piezoelectric elements are used to excite and sense the waves. The behavior of the systems studied are widely discussed in frequency and time domains. In order to detect and quantify the damage, reflected waves showed better sensitivity and proportionality with damage severity for all configuration studied. The longitudinal wave incident in the damage is easier to be used in a SHM system than flexural waves because longitudinal waves present simplicity compared to flexural. However, is important to choose appropriate frequency range in order to generate good levels of the longitudinal waves.