Avaliação da eficácia da técnica de excitação por impulso para detecção da influência de defeitos na rigidez da madeira de Eucalyptus urograndis

• Autor(a) principal: Martins, Jorge Carvalho [UNESP]
• Data de Publicação: 2017
• Tipo de documento: Trabalho de conclusão de curso
• Idioma: por
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://hdl.handle.net/11449/203708; http://www.athena.biblioteca.unesp.br/exlibris/bd/capelo/2020-01-20/000919594.pdf
• topic: Madeira - Testes; Testes não-destrutivos; Madeira - Defeitos; Madeira - Propriedades mecânicas; Elasticidade; Eucalipto; Wood - Testing

Wood is a natural material with variability in its mechanical properties influenced by characteristic abnormalities of the tree formation. It is important to know mechanical aspects of the material, as stiffness, to use it in a more conscious way, mainly in structural parts. Several methods have been used for this purpose, with noteworthy growth in non-destructive techniques. The main objective of this study is to analyze the effectiveness of the impulse excitation technique to characterize the stiffness of Eucalyptus urograndis 12 years old containing defects, from Itapeva/SP region. For characterization, the non-destructive impulse excitation method was used through the Sonelastic® PC Based Technology, and it was analyzed the coherence of this technique with the results obtained by the traditional destructive method of static bending. Three groups of specimens were prepared (healthy wood, with natural defect and with dowels inserted in the center of the sample) with nominal dimension of 5 cm x 5 cm x 115 cm. The mean values of modulus of elasticity found for the groups of defective specimens were lower than the healthy woods samples in the two methods analyzed. It was noticed correspondence between the results obtained by the two techniques, with correlation coefficient greater than 0,90. For all three groups analyzed, the values of the dynamic modulus of elasticity were higher than the static ones. It is concluded that the impulse excitation technique is effective to characterize wood stiffness containing defects, proving to be a reliable technique of quick and easy application