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Peeling industry is the most important outlet for poplar resource composed of many cultivars. A comprehensive evaluation of wood quality of these different cultivars is necessary for a better knowledge of their suitability for innovative applications, like LVL for construction, in order to help foresters in their choices. This research participates to this approach, focusing on mechanical properties of LVL boards produced from ten cultivars, having grown in four different soils. Two trees were harvested per soil type and per cultivar; the tests were performed on eighty trees, which were peeled 1.4 mm thick and 3 mm thick. The produced veneers were used to manufacture 160 LVL boards using two adhesives: polyvinyl acetate (PVAc) and melamine–urea–formaldehyde (MUF). Each board was characterized by non-destructive and destructive mechanical tests, measuring their density, modulus of elasticity and modulus of rupture. The results show that the boards’ mechanical performance is neither linked to veneer thickness nor adhesive type. No cultivar or soil effect was clearly identified. The studied cultivars are not suitable for structural applications. Nevertheless, a discussion about an increase in the poplar rotation duration seems relevant in order to be able to use this wood for construction.

The aim of this paper is to study the possible influence of poplar cultivar and soil on the mechanical properties of plywood produced from 10 cultivars having grown in different soils. For each cul...

This paper introduces a new test configuration for the determination of panel shear properties in structural sizes. This original test configuration has been successfully applied to calculate the shear properties of beech plywood. A numerical model has been developed to evaluate the influence of such a novel setup in comparison to the common standard. The research includes the mechanical characterization of a total of 36 samples using Digital Image Correlation (DIC) to measure the in plane displacements. The use of DIC has been proven to be efficient to measure the shear properties and also acts as a tool to ensure that the solicitation was adequate during the test. Finally, the results highlight the interest to actually perform the proposed test instead of using the alternative density-based equivalencies provided by the standards. ANR-10-EQPX-16 XYLOFOREST LabMixte BOPLI (ENSAM & Région Bourgogne-Franche-Compté)

International audience; In dieser Studie wird ein neues Verfahren zur Messung von Rissen in Furnieren unter Verwendung digitaler Bildanalyse untersucht. Dabei ist die Kamera seitlich angeordnet, wodurch die Rissgeometrie auf einer Querschnittsseite des Furniers betrachtet werden kann. Durch Biegen des Furniers auf einer Rolle mit spezifischem Durchmesser werden die Risse geöffnet und so belichtet, dass diese gut sichtbar sind. Der verwendete Algorithmus bestimmt die Risse, indem er zunächst in einem Bild mit verringerter Auflösung deren ungefähre Position feststellt und dann an diesen Stellen im Originalbild mit voller Auflösung die Risstiefe genau erfasst. Es handelt sich um ein automatisches Verfahren, das die wichtigsten Informationen zur Rissbildung, nämlich den Abstand zwischen den Rissen und deren Tiefe, liefert.; In the present paper, a novel method for veneer checks measurement and description based on digital image analysis is evaluated. According to this method, the camera is located sideways to the veneer allowing for viewing the checks geometry in the cross-section of the veneer. Checks are opened by bending the veneer on a roller of a specific diameter and they are exposed in such a way that good visibility of checks is assured. The algorithm used reproduces the checks by finding their coarse positions on the rescaled image and then migrating to the original, full resolution image to precisely localize the checks' bottom. The method is automatic and delivers the most important information on checks of veneer, namely distances between checks and their depths.

This paper uses the cutting forces in a routing process of Aleppo pine wood to estimate the tool wear effect. The aim is to obtain further information about the tool wear effect by monitoring the variation in the cutting forces. A Kistler 9257A 3 axes Dynamometer was positioned under the workpiece to measure the cutting forces at frequencies up to 10,000 Hz. The experiments were carried out on a CNC routing machine RECORD1 of SCM. A carbide tool was used and the cutting parameters were fixed. The cutting speed was approximately 25 m/s. Dasylab software was used to capture the data. The results show a correlation between the tool wear and the computed angle ( ), between the tangential and cutting forces. In fact, the variation of ( ) is unstable in the running period and stable in the linear wear zone, included in the interval [−1.11°; −1.10°]. This study was performed as part of a development program for the Algerian wood industry, hence the selection Aleppo pine wood as the working material. FCBA Institut Technologique, FSE (Fond Social Européen), CRB (Conseil Régional de Bourgogne) and University of Boumerdes (Algeria)

Comparaison entre un bois très commun et usiné en Europe comme le pin Douglas et une essence pas très utilisée comme le pin d'Alep de provenance algérienne. Pour cette comparaison, une nouvelle méthode a été mise au point afin d'évaluer les efforts de coupe et la qualité des surfaces usinées dans le processus du défonçage. Cette méthode a été expérimentée sur du pin d'Alep en coupe orthogonale allant de façon continue de 90°/0° à 90°/90° dans le sens du fil et contrefil afin de juger également de l'aptitude à l'usinage de ce bois par rapport à d'autres essences plus communément usinées. L'outil de coupe est une fraise circulaire comportant deux plaquettes en carbure. Elle est utilisée pour usiner le chant de disques de pin d'Alep prélevés dans une planche, ce qui induit une variation de l'angle du fil continue de 0° à 360°. La mesure des forces de coupe a été faite avec l'emploi d'une table piézoélectrique Kistler 9257A à trois axes montée sur la table d'une défonceuse à commande numérique, couplée à un PC et une carte d'acquisition. Les données sont traitées à l'aide d'un logiciel Dasylab. Parallèlement, des tests de qualité des surfaces usinées avec un outil comportant une arête de coupe neuve sur une moitié et usée artificiellement sur l'autre ont été réalisés par une nouvelle méthode sans contact développée par l'équipe de recherche Cnr/Ivalsa. Les résultats indiquent que les efforts de coupe sont un peu plus grands pour le pin Douglas que pour le pin d'Alep. En revanche, la qualité des surfaces obtenues est bien meilleure pour le pin d'Alep que pour le pin Douglas.