Performance of strength grading methods based on fibre orientation and axial resonance frequency applied to Norway spruce (Picea abies L.), Douglas fir (Pseudotsuga menziesii (Mirb.) Franco) and European oak (Quercus petraea (Matt.) Liebl./Quercus robur L.)
Article dans une revue avec comité de lecture
Key message Machine strength grading of sawn timber is an important value adding process for the sawmilling industry. By utilizing data of local fibre orientation on timber surfaces, obtained from laser scanning, more accurate prediction of bending strength can be obtained compared to if only axial vibratory measurements are performed. However, the degree of improvement depends on wood species and on board dimensions. It is shown that a model based on a combination of fibre orientation scanning and axial vibratory measurement is very effective for Norway spruce ( Picea abies L.) and Douglas fir ( Pseudotsuga menziesii (Mirb.) Franco). For European oak ( Quercus petraea (Matt.) Liebl./ Quercus robur L.) boards of narrow dimensions, axial vibratory measurements are ineffective whereas satisfactory results are achieved using a model based on fibre orientation. ContextMachine strength grading of sawn timber is an important value adding process for the sawmilling industry.AimsThe purpose of this paper has been to compare the accuracy of several indicating properties (IPs) to bending strength when applied to Norway spruce (Picea abies L.), Douglas fir (Pseudotsuga menziesii (Mirb.) Franco) and European oak (Quercus petraea (Matt.) Liebl./Quercus robur L.).MethodsThe IPs were determined for a set of data comprising scanned high-resolution information of fibre orientation on board surfaces, axial resonance frequency, mass and board dimensions.ResultsWhereas dynamic axial modulus of elasticity (MoE) gave good prediction of bending strength of Norway spruce (R2 = 0.58) and Douglas fir (R2 = 0.47), it did not for narrow dimension boards of oak (R2 = 0.22). An IP based on fibre orientation gave, however, good prediction of bending strength for all three species and an IP considering both dynamic axial MoE and local fibre orientation for prediction of bending strength gave very good accuracy for all species (Norway spruce R2 = 0.72, Douglas fir R2 = 0.62, oak R2 = 0.59). Comparisons of results also showed that scanning of fibre orientation on all four sides of boards resulted in more accurate grading compared to when only the two wide faces were scanned.ConclusionData of local fibre orientation on wood surfaces give basis for accurate machine strength grading. For structural size timber of Norway spruce and Douglas fir, excellent grading accuracy was achieved combining such data with data from vibratory measurements. The improvements achieved enable substantial increase of yield in high-strength classes.
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Performance of timber board models for prediction of local bending stiffness and strength—with application on douglas fir sawn timber Article dans une revue avec comité de lectureOLSSON, Anders; POT, Guillaume; VIGUIER, Joffrey; HU, Min; OSCARSSON, Jan (2022)Efficient utilization of structural timber requires accurate methods for machine strength grading. One of the most accurate methods presented this far is based on data of local fiber orientation on board surfaces, obtained ...
Communication avec actePENVERN, Hélène; POT, Guillaume; VIGUIER, Joffrey; COLLET, Robert; DEMOULIN, Leyne; ROUX, Benjamin; OLSSON, Anders; HU, Min (2023-09-05)This work is exhibiting a new laboratory investigation method to obtain fibre 3D angle measurement of a wood piece after successive planing of the whole specimen. By combining in-plane fibre measurements through laser ...
Traceability and quality assessment of Douglas fir (Pseudotsuga menziesii (Mirb.) Franco) logs: the TreeTrace_Douglas database Article dans une revue avec comité de lectureLONGUETAUD, Fleur; POT, Guillaume; MOTHE, Frédéric; BARTHELEMY, Alexis; DECELLE, Rémi; DELCONTE, Florian; GE, Xihe; GUILLAUME, Grégoire; MANCINI, Théo; RAVOAJANAHARY, Tojo; BUTAUD, Jean-Claude; COLLET, Robert; DEBLED-RENNESSON, Isabelle; MARCON, Bertrand; NGO, Phuc; ROUX, Benjamin; VIGUIER, Joffrey (Springer Science and Business Media LLC, 2022-11-28)The TreeTrace_Douglas database includes images and measurements at several stages of the processing of Douglas fir logs, from sawmill logyard to machine grading and destructive testing of boards, and is suitable for research ...
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The influence of veneer thickness and knot proportion on the mechanical properties of laminated veneer lumber (LVL) made from secondary quality hardwood Article dans une revue avec comité de lecturePURBA, Citra Yanto Ciki; POT, Guillaume; VIGUIER, Joffrey; RUELLE, Julien; DENAUD, Louis (Springer Verlag, 2019)The first objective of this work was to study the influence of veneer quality on the mechanical properties of laminated veneer lumber (LVL) made of secondary quality hardwood. The second objective was to propose an adapted ...