Modelagem dos defeitos na madeira de >i<Eucalyptus grandis>/i< oriundos da tensão de crescimento

Abstract

Modeling defects in Eucalyptus grandis wood generated by growth stressesGrowth stress generates several defects in the wood, which include cracking and warping. These defects are very common and are present in different varieties of eucalyptus, whose species are important to Brazilian forestry, despite the high presence of growth stresses in their woods. The growth tension is one of the biggest impediments to the use of this wood in nobler uses in the country. Measuring wood defects before processing improves productivity forecasts and planning of the cutting stages, the results of which support the more efficient use of wood and also generate new scientific knowledge about its species. This dissertation aims to model log end cracks, bending deflections in Eucalyptus grandis lumber and to compare longitudinal growth stress distribution models. Five distinct longitudinal growth stress distribution models were used together with structural engineering equations to perform the modeling. The boards of the experiment were collected from an industrial timber processing that produced boards with tangential cut, in total twenty boards from four Eucalyptus grandis logs were used. As a result, it was found that the crack profiles are consistent with previous studies, as there was little difference in the behavior of the five models. Regarding the deflection models, at least one interpretation obtained a good correlation with the bending deflections, being able to perform its prediction. The linear distribution proved to be the most suitable for modeling the bending deflections.