tailieunhanh - Báo cáo khoa học: "Predicting oak wood properties using X-ray inspection: representation, homogenisation and localisation. Part I: Digital X-ray imaging and representation by finite elements"

Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp quốc tế đề tài: Predicting oak wood properties using X-ray inspection: representation, homogenisation and localisation. Part I: Digital X-ray imaging and representation by finite elements. | Ann. For. Sci. 59 2002 767-776 INRA EDP Sciences 2002 DOI forest 2002063 767 Original article Predicting oak wood properties using X-ray inspection representation homogenisation and localisation. Part I Digital X-ray imaging and representation by finite elements Éric Badel and Patrick Perré Laboratoire d Etude et de Recherche sur le Matériau Bois UMR 1093 INRA ENGREF Université Henri Poincaré Nancy I ENGREF 14 rue Girardet 54042 Nancy Cedex France Received 8 January 2002 accepted 21 May 2002 Abstract - This paper is the first part of a complete modelling where wood is a 2D composite material. It proposes a comprehensive approach to predict the elastic and shrinkage properties of oak wood in the transverse plane from the local properties of the anatomical tissues and the actual morphology of those tissues. Part I is devoted to the methodology of representation. According to oak anatomy the representative elementary volume used in this work consists of one annual ring limited in the tangential direction by large zones of ray cells. A high-resolution digital X-ray imaging device was built to represent the spatial distribution of tissues directly from cross-sections of wood. A complete image processing including image segmentation and partitioned boundaries of tissues ray cells big vessels etc. was developed which makes it possible to build a finite element mesh from these images. Thanks to the control of mesh refinement the number of triangular elements is minimized while a good description of the anatomical structure is obtained. Using these . meshes Part II will present the homogenization principle and a few examples of calculations of the properties. Macroscopic properties mechanical and shrinkage and some localization problems are computed and illustrated. wood anatomy image X-ray finite element mesh Résumé - Utilisation de l imagerie X pour la prediction du bois de chêne representation homogénéisation et localisation. Partie I Imagerie X numérique et .