Defect Detection in Anisotropic Plates Based on the Instantaneous Phase of Signals

Autor(es)

Prado, Vander Teixeira ^[1] ; Garcia Granja, Silvio Cesar ^[2] ; Higuti, Ricardo Tokio ^[3] ; Kitano, Claudio ^[3] ; Martinez-Graullera, Oscar ^[4] ; Elvira Segura, Luis ^[4]

Afiliação do(s) autor(es)

^[1] Univ Tecnol Fed Parana, Dept Elect Engn, BR-86399000 Cornelio Procopio, PR - Brazil

^[2] Univ Estado Mato Grosso, Fac Ciencias Exatas & Tecnol, Dept Math, BR-78555000 Sinop, MT - Brazil

^[3] Univ Estadual Paulista, Fac Engn Ilha Solteira, Dept Elect Engn, BR-15385000 Ilha Solteira, SP - Brazil

^[4] Inst Tecnol Fis & Informac Leonardo Torres Qu, Madrid 28006 - Spain

• Tipo de documento: Artigo Científico
• Fonte: IEEE TRANSACTIONS ON ULTRASONICS FERROELECTRICS AND FREQUENCY CONTROL; v. 62, n. 10, p. 1888-1894, OCT 2015.
• Citações Web of Science: 1

Resumo

Anisotropic materials are widely employed in industry and engineering, and efficient nondestructive testing techniques are important to guarantee the structural integrity of the involved parts. A simple technique is proposed to detect defects in anisotropic plates using ultrasonic guided waves and arrays. The technique is based on the application of an objective threshold to a synthetic aperture image obtained from the instantaneous phase (IP) of the emitter-receiver signal combinations. In a previous work the method was evaluated for isotropic materials, and in this paper it is shown that with some considerations the technique can also be applied to anisotropic plates. These considerations, which should be taken into account in beamforming, are (1) group velocity dependence with propagation direction, and (2) elastic focusing, which results in energy concentration in some propagation directions, with the practical consequence that not all aperture signals effectively contribute to the image. When compared with conventional delay-and-sum image beamforming techniques, the proposed IP technique results in significant improvements relative to defect detection and artifacts/dead zone reduction. (AU)

• Processo FAPESP: 14/08790-3 - Métodos para melhoria da qualidade de imagens ultrassônicas a partir da fase dos sinais e processamento digital de sinais
• Beneficiário: Vander Teixeira Prado
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado