Extensiometria óptica por Moiré geométrico digital para anãlise de tensões no plano / Optical extensometry by digital geometric Moiré for in-plane stress analysis

AUTOR(ES)
FONTE

IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia

DATA DE PUBLICAÇÃO

20/06/2011

RESUMO

The study of the behavior of building structures pass through the determination of the strain and stresses to evaluate the level of local and global security against the active actions. In the last years in Brazil, the extensometers have been commonly used to measure the strain at a specific single point. The optical extensometry presents itself as an alternative to this task by providing results for all points of measurement area (full field). The moiré techniques are the simplest of the optical extensometry and have the smaller indeces relating to noise. In this work, the sensitivity of mechanics (or geometric) interference of moiré technique reached levels that previously could only be obtained using interferometers (moiré interferometry). It is worth noting that interferometers are appliances that cost thousands of dollars. This task was made possible through the multiplication of fringes obtained through digital technology with application present in photography and digital image processing and proved able to measure deformations for micrometric from very low frequency cross gratings. This work is presented as digital geometric moiré technique (TMGD) because everything from image capture of specimen gratings until the generation of fringes was made by digital means and therefore does not fall within the classification set out in chapter which deals with the classification of moiré techniques. The result was something still unheard in civil engineering in Brazil, a low-cost technique, insensitive to vibrations and of the environment, moreover able to make measurements in plane surfaces without major apparatus. Findings show the applicability of the proposed method to measure strain and to analyze stresses in models and civil engineering structures

ASSUNTO(S)

método de moiré mecânica dos sólidos deformação e tensões - medição method of moiré solid mechanics strain and stresses

ACESSO AO ARTIGO

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