Application of moiré technique on strain analysis in farm machinery elements

Abstract

-Development and optimization of projects for agricultural machinery involve the analysis of stress and strain. Moiré photomechanical techniques provide a complete displacement field of the specimen under test, and can aid in understanding the mechanical behavior of parts with complex geometry. Hybrid methods combine fringe patterns of displacement with distribution maps of stress and strain through concepts of the theory of elasticity. The objective of this work was to analyse the use of the shadow moiré technique in the qualitative determination of stress and strain distribution in geometrically complex machine elements. The results were compared with those from an electrical extensometer and a computer simulation. The results demonstrated that the shadow moire technique was quite reliable in analysing the mechanical behavior of geometrically complex machine elements.

Classificação de laranjas através da técnica de moiré por phase-shifing

“…Uma das maneiras de se obter dados geométricos de corpos é através do uso de técnicas ópticas, destaca-se a Técnica de Moiré (TM). O fenômeno Moiré ocorre quando duas grades ópticas com certa densidade são superpostas, havendo um movimento relativo entre elas, gerando um conjunto de faixas semelhante a ondas, com ângulo e período diferenciados das duas telas iniciais (CARDOSO et al, 2014). Esse terceiro grupo de faixas é denominado "franjas de Moiré" e variam da cor escura, gerada por ondas de interferência destrutiva, a cor clara total, gerada por ondas de interferência construtivas (BERALDO et al, 2007).…”

Simple and low-cost interferogram projection system for small-size automotive parts profilometry: benchmarking with a commercial apparatus

“…Since those techniques provide non-contact testing, they are very suitable for measuring delicate and soft textures, like e.g. in quality control of vegetable shape and aging in agricultural engineering (Cardoso et al, 2014) or in evaluation of the retina in ophthalmology procedures (Drexler et al, 2001). Low-coherence speckle metrology enabled also good results in lens characterization (Barbosa et al, 2013) and laser scanning provided applications in historical restoration (Liang et al, 2016).…”