Abstract
The cylindrical orthotropy, inherent time-dependency response, and variation between and within samples make the stiffness characterisation of wood more challenging than most other structural materials. The purpose of the present study is to compare static loading with resonant ultrasound spectroscopy (RUS) and to investigate how to combine the advantages of each of these two methods to improve the estimation of the full set of elastic parameters of a unique sample. The behavior of wood as an orthotropic mechanical material was quantified by elastic engineering parameters, i.e. Poisson’s ratios and Young’s and shear moduli. Recent and waterlogged archaeological oak impregnated with polyethylene glycol (PEG) from the Vasa warship built in 1628 was in focus. The experimental results were compared, and the difference between RUS and static loading was studied. This study contributes additional information on the influence of PEG and degradation on the elastic engineering parameters of wood. Finally, the shear moduli and Poisson’s ratios were experimentally determined for Vasa archaeological oak for the first time.
Acknowledgments
This article was produced in collaboration with the National Maritime Museums and, in particular, the Vasa Museum. The work has been carried out within the “Support Vasa” project. Financial support for short-term scientific missions from EU COST Action FP1101 (Assessment, Reinforcement and modelling of Timber structures) is gratefully acknowledged.
References
Bader, T.K., Eberhardsteiner, J., de Borst, K. (2015) Shear stiffness and its relation to the microstructure of 10 European and tropical hardwood species. Wood Mat. Sci. Eng.: 1–10. Doi: 10.1080/17480272.2015.1030773.Search in Google Scholar
Bjurhager, I., Halonen, H., Lindfors, E.-L., Iversen, T., Almkvist, G., Gamstedt, E.K., Berglund, L.A. (2012) State of degradation in archeological oak from the 17th century Vasa ship: substantial strength loss correlates with reduction in (holo)cellulose molecular weight. Biomacromolecules 13:2521–2527.10.1021/bm3007456Search in Google Scholar PubMed
Bjurhager, I., Ljungdahl, J., Wallström, L., Gamstedt, E.K., Berglund, L.A. (2010) Towards improved understanding of PEG-impregnated waterlogged archaeological wood: a model study on recent oak. Holzforschung 64:243–250.10.1515/hf.2010.024Search in Google Scholar
Bodig, J., Jayne, B. Mechanics of Wood and Wood Composites. Van Nostrand Reinhold, New York, 1982.Search in Google Scholar
Bucur, V. Acoustics of Wood. Springer Series in Wood Science. Springer, Berlin, Heidelberg, 2006.10.1007/3-540-30594-7Search in Google Scholar
Cederlund, C.O., Hocker, F. (2006) Vasa I: the archaeology of a Swedish royal ship of 1628. In: Statens Maritima Museer. National Maritime Museum of Sweden.Search in Google Scholar
Dahl, K.B., Malo, K.A. (2009) Planar strain measurements on wood specimens. Exp. Mech. 49:575–586.10.1007/s11340-008-9162-0Search in Google Scholar
de Borst, K., Bader, T.K., Wikete, C. (2012) Microstructure stiffness relationships of ten European and tropical hardwood species. J. Struct. Biol. 177:532–542.10.1016/j.jsb.2011.10.010Search in Google Scholar PubMed
Gonçalves, R., Trinca, A.J., Cerri, D.G.P. (2011) Comparison of elastic constants of wood determined by ultrasonic wave propagation and static compression testing. Wood Fiber Sci. 43:64–75.Search in Google Scholar
Gonçalves, R., Trinca, A.J., Pellis, B.P. (2014) Elastic constants of wood determined by ultrasound using three geometries of specimens. Wood Sci. Technol. 48:269–287.10.1007/s00226-013-0598-8Search in Google Scholar
Guitard, D., El Amri, F. (1987) Modèles prévisionnels de comportement élastique tridimensionnel pour les bois feuillus et les bois résineux. Ann. Sci. Forest. 44:335–358.10.1051/forest:19870305Search in Google Scholar
Hassel, I., Berard, P., Moden, C.S., Berglund, L.A. (2009) The single cube apparatus for shear testing – Full-field strain data and finite element analysis of wood in transverse shear. Compos. Sci. Technol. 69:877–882.10.1016/j.compscitech.2008.11.013Search in Google Scholar
Hearmon, R.F.S. Elasticity of wood and plywood. Report No. 7. HM Stationary Office, London, 1948.Search in Google Scholar
Hepworth, D.G., Vincent, I.F., Stringer, G., Jeronimidis, G. (2002) Variations in the morphology of wood structure can explain why hardwood species of similar density have very different resistance to impact and compressive loading. Philos. T. R. Soc. A 360:255–272.10.1098/rsta.2001.0927Search in Google Scholar PubMed
Huang, Y. H., Liu, L., Sham, F.C., Chan, Y.S., Ng, S.P. (2010) Optical strain gauge vs. traditional strain gauges for concrete elasticity modulus determination. Optik 121:1635–1641.10.1016/j.ijleo.2009.03.002Search in Google Scholar
Kollmann, F. (1968) Mechanics and rheology of wood. In: Principle of Wood Science and Technology – 1. Solid Wood. Eds. Kollmann, F.P., Côté, W.A. Springer-Verlag, New York. pp. 292–419.10.1007/978-3-642-87928-9_7Search in Google Scholar
Ljungdahl, J., Berglund, L. (2007) Transverse mechanical behaviour and moisture absorption of waterlogged archaeological wood from the Vasa ship. Holzforschung 61:279–284.10.1515/HF.2007.048Search in Google Scholar
Longo, R., Delaunay, T., Laux, D., El Mouridi, M., Arnould, O., Le Ciezio, E. (2012) Wood elastic characterization from a single sample by resonant ultrasound spectroscopy. Ultrasonics 52:971–974.10.1016/j.ultras.2012.08.006Search in Google Scholar
Longo, R., Laux, D., Pagano, S., Delaunay, T., Le Clezio, E., Arnould, O., (2014) Caractérisation élastique de bois de différentes densités par spectroscopie ultrasonore résonante (RUS). In: Matériaux 2014 – Conférence pluridisciplinaire sur les matériaux, 24–28 novembre 2014, Montpellier, France.Search in Google Scholar
Majano-Majano, A., Fernandez-Kabo, J.L., Hoheisel, S., Klein, M. (2012) A test method for characterizing clear wood. Exp. Mech. 52:1079–1096.10.1007/s11340-011-9560-6Search in Google Scholar
Migliori, A., Darling, T.W., Baiardo, J.P., Freibert, F. (2001) Resonant ultrasound spectroscopy (RUS). In: Experimental Methods in the Physical Sciences. Eds. Levy, M., Bass, H.E., Stern, R. Elsevier. Vol. 39, pp. 189–220.Search in Google Scholar
Ozyhar, T., Hering, S., Niemz, P. (2013) Moisture-dependent orthotropic tension-compression asymmetry of wood. Holzforschung 67:395–404.10.1515/hf-2012-0089Search in Google Scholar
Rakotovololonalimanana, H., Chaix, G., Brancheriau, L., Ramamonjisoa, L., Ramananantoandro, T., Thevenon, M.F. (2015) A novel method to correct for wood MOE ultrasonics and NIRS measurements on increment cores in Liquidambar styraciflua L. Ann. For. Sci. 1-9. 10.1007/s13595-015-0469-6.Search in Google Scholar
Schubert, S.I., Gsell, D., Dual, J., Motavalli, M., Niemz, P. (2006) Rolling shear modulus and damping factor of spruce and decayed spruce estimated by modal analysis. Holzforschung 60:78–84.10.1515/HF.2006.014Search in Google Scholar
Smith, I., Landis, E., Gong, M. Fracture and fatigue in wood. John Wiley and Sons, New York, 2003.Search in Google Scholar
Sjödahl, M., Synnergren, P. (1999) A stereoscopic digital speckle photography system for 3-D displacement field measurements. Opt. Laser Eng. 31:425–443.10.1016/S0143-8166(99)00040-8Search in Google Scholar
Toftegaard, H. (1999) Simulated stiffness determination from simple compression tests on a thick laminate. Compos. Part A-Appl. S. 30:849–858.10.1016/S1359-835X(98)00199-7Search in Google Scholar
Tsoumis, G. Science and technology of wood. Structure, properties, utilization. Van Nostrand Reinhold, 1991.Search in Google Scholar
Vázquez, C., Gonçalves, R., Bertoldo, C., Baño, V., Vega, A., Crespo, J., Guaita, M. (2015) Determination of the mechanical properties of Castanea sativa Mill. using ultrasonic wave propagation and comparison with static compression and bending methods. Wood Sci. Technol. 49:607–622.10.1007/s00226-015-0719-7Search in Google Scholar
Volkmer, T., Lorenz, T., Hass, P., Niemz, P. (2014) Influence of heat pressure steaming (HPS) on the mechanical and physical properties of common oak wood. Eur. J. Wood Prod. 72: 249–259.10.1007/s00107-014-0777-9Search in Google Scholar
Xavier, J., de Jesus, A.M.P., Morais, J.L.L., Pinto, J.M.T. (2012) Stereovision measurements on evaluating the modulus of elasticity of wood by compression tests parallel to the grain. Constr. Build. Mater. 26:207–215.10.1016/j.conbuildmat.2011.06.012Search in Google Scholar
Zadler, B.J., Le Rousseau, J.H., Scales, J.A., Smith, M.L. (2004) Resonant ultrasound spectroscopy: theory and application. Geophys. J. Int. 156:154–169.10.1190/1.1817048Search in Google Scholar
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