Abstract
A moisture content effect on fracture characterisation of Pinus pinaster under mode I is addressed. The double cantilever beam test is selected for mode I loading, based on specimens scaled down to the growth ring level. Specimens are stabilised using aqueous solutions at several equilibrium moisture contents (\( M_{\text{e}} \)) ranging from 0 % to about 13 %. The strain energy release rate (\( G_{\text{I}} \)) is evaluated by applying the compliance-based beam method, from which the Resistance-curve is determined directly from load–displacement (P–δ) data without crack length measurement. The crack tip opening displacement in mode I (\( w_{\text{I}} \)) is determined by post-processing the displacements at the initial crack tip determined from digital image correlation. \( G_{\text{I}} \) and \( w_{\text{I}} \) are then combined for the direct identification of the cohesive law, \( \sigma_{\text{I}} = {\text{f}}(w_{\text{I}} ) \), which is assumed in cohesive zone modelling. Experimentally, crack propagation consistently occurs in the earlywood layer. The increase of \( M_{\text{e}} \) does not show any influence on the initiation stage of the fracture process zone. However, a statistical correlation exists for the critical (\( G_{\text{I,max}} \)) and at maximum load (\( G_{{{\text{I,}}P_{ \hbox{max} } }} \)) values of \( G_{\text{I}} \) with regard to \( M_{\text{e}} \). Consistently, the area under the identified cohesive curve increases with \( M_{\text{e}} \), although high scatter and low correlation between maximum cohesive strength (\( \sigma_{\text{Iu}} \)) and \( M_{\text{e}} \) are observed. The methodology is also validated using finite element analysis including cohesive elements and taking into account the growth rings heterogeneity. The numerical results show that the identification of the cohesive law is insensitive to the variability of the growth ring structure observed experimentally.
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References
Stehn L (2002) Environmental labelling of timber-framed dwellings and their building components. Build Res Inf 30:248–254
Gustavsson L, Sathre R (2006) Variability in energy and carbon dioxide balances of wood and concrete building materials. Build Environ 41:940–951
Xavier J, Avril S, Pierron F, Morais J (2007) Novel experimental approach for longitudinal-radial stiffness characterisation of clear wood by a single test. Holzforschung 61:573–581
Xavier J, Avril S, Pierron F, Morais J (2009) Variation of transverse and shear stiffness properties of wood in a tree. Compos Part A 40:1953–1960
Pereira J, Xavier J, Morais J, Lousada J (2014) Assessing wood quality by spatial variation of elastic properties within the stem: case study of P. pinaster in the transverse plane. Can J For Res 44:107–117
King MJ, Sutherland IJ, Le-Ngoc L (1999) Fracture toughness of wet and dry Pinus radiata. Holz als Roh- und Werkst 57:235–240
Rhême M, Botsis J, Cugnoni J, Navi P (2013) Influence of the moisture content on the fracture characteristics of welded wood joint. Part 1: mode I fracture. Holzforschung 67:747–754
Majano-Majano A, Hughes M, Fernandez-Cabo J (2012) The fracture toughness and properties of thermally modified beech and ash at different moisture contents. Wood Sci Technol 46:5–21
de Moura MFSF, Morais JJL, Dourado N (2008) A new data reduction scheme for mode I wood fracture characterization using the double cantilever beam test. Eng Fract Mech 75:3852–3865
Dourado N, de Moura MFS, Morais JL, Silva MAL (2010) Estimate of resistance-curve in wood through double cantilever beam test. Holzforschung 64:119–126
Xavier J, Oliveira J, Monteiro P, Morais JJL, de Moura MFSF (2014) Direct evaluation of cohesive law in mode I of Pinus pinaster by digital image correlation. Exp Mech. doi:10.1007/s11340-013-9838-y
Bigorgne L, Brunet M, Maigre H, Simon P, Chaudet P (2011) Investigation of softwood fracture criteria at the mesoscopic scale. Int J Fract 172:65–76
Nairn J (2007) Material point method simulations of transverse fracture in wood with realistic morphologies. Holzforschung 61:375–381
Smith I, Landis E, Gong M (2003) Fracture and fatigue in wood. Wiley, Chichester
Elices M, Guinea GV, Gómez J, Planas J (2002) The cohesive zone model: advantages, limitations and challenges. Eng Fract Mech 69:137–163
Fernberg SP, Berglund LA (2001) Bridging law and toughness characterisation of CSM and SMC composites. Compos Sci Technol 61:2445–2454
Xavier JC, Garrido NM, Oliveira M, Morais JL, Camanho PP, Pierron F (2004) A comparison between the Iosipescu and off-axis test methods for the characterization of Pinus pinaster Ait. Compos Part A 35:827–840
Xavier J, Oliveira M, Morais J, Pinto J (2009) Measurement of the shear properties of clear wood by the Arcan test. Holzforschung 63:217–225
Dias GF, de Moura MFSF, Chousal JAG, Xavier J (2013) Cohesive laws of composite bonded joints under mode I loading. Compos Struct 106:646–652
Grédiac M (2004) The use of full-field measurement methods in composite material characterization: interest and limitations. Compos Part A 35:751–761
Sutton M, Orteu J-J, Schreier H (2009) Image correlation for shape, motion and deformation measurements: Basic concepts, theory and applications. Springer, New York
Réthoré J, Hild F, Roux S (2007) Shear-band capturing using a multiscale extended digital image correlation technique. Comput Method Appl M 196:5016–5030
Réthoré J, Hild F, Roux S (2008) Extended digital image correlation with crack shape optimization. Int J Numer Methods Eng 73:248–272
Dubois F, Méité M, Pop O, Absi J (2012) Characterization of timber fracture using the Digital Image Correlation technique and finite element method. Eng Fract Mech 96:107–121
Méité M, Pop O, Dubois F, Absi J (2013) Characterization of mixed-mode fracture based on a complementary analysis by means of full-field optical and finite element approaches. Int J Fract 180:41–52
Silva F, Xavier J, Pereira FAM, Morais J, Dourado N, de Moura MFSF (2013) Determination of cohesive laws in wood bonded joints under mode I loading using the DCB test. Holzforschung 67:913–922
Silva F, Morais J, Dourado N, Xavier J, Pereira FAM, de Moura MFSF (2014) Determination of cohesive laws in wood bonded joints under mode II loading using the ENF test. Int J Adhes Adhes 51:54–61
Sousa AMR, Xavier J, Morais JJL, Filipe VMJ, Vaz M (2011) Processing discontinuous displacement fields by a spatio-temporal derivative technique. Opt Laser Eng 49:1402–1412
ASTM E 104-85. Standard practice for maintaining constant relative humidity by means of aqueous solutions. American Society for Testing and Materials, Philadelphia, PA, USA, 1991
GOM mbH (2007) ARAMIS DIC 2D/3D commercial software, ARAMIS 6.0.2
Xavier J, de Jesus AMP, Morais JJL, Pinto JMT (2012) Stereovision measurements on evaluating the modulus of elasticity of wood by compression tests parallel to the grain. Constr Build Mater 26:207–215
Sousa AMR, Xavier J, Vaz M, Morais JJL, Filipe VMJ (2011) Cross-correlation and differential technique combination to determine displacement fields. Strain 47:87–98
de Moura MFSF, Goncalves JPM, Marques AT, de Castro PMST (1997) Modeling compression failure after low velocity impact on laminated composites using interface elements. J Compos Mater 31:1462–1479
Silva MAL, de Moura MFSF, Morais JJL (2006) Numerical analysis of the ENF test for mode II wood fracture. Compos Part A 37:1334–1344
Reiterer A, Tschegg S (2002) The influence of moisture content on the mode I fracture behaviour of sprucewood. J Mater Sci 37:4487–4491. doi:10.1023/A:1020610231862
Engelund ET, Thygesen LG, Svensson S, Hill CAS (2013) A critical discussion of the physics of wood–water interactions. Wood Sci Technol 47:141–161
Kifetew G, Thuvander F, Berglund L, Lindberg H (1998) The effect of drying on from specimens loaded wood fracture surfaces in wet condition. Wood Sci Technol 32:83–94
Reiterer A, Sinn G, Stanzl-Tschegg SE (2002) Fracture characteristics of different wood species under mode I loading perpendicular to the grain. Mater Sci Eng A332:29–36
Acknowledgements
This work was supported by European Union Funds (FEDER/COMPETE—Operational Competitiveness Programme) and by National Funds (FCT—Portuguese Foundation for Science and Technology) under the Project FCOMP-01-0124-287 FEDER-022692. The authors would like to acknowledge the support of FCT under the Project PTDC/EME-PME/114443/2009 and Ciência 2008 program.
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Xavier, J., Monteiro, P., Morais, J.J.L. et al. Moisture content effect on the fracture characterisation of Pinus pinaster under mode I. J Mater Sci 49, 7371–7381 (2014). https://doi.org/10.1007/s10853-014-8375-0
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DOI: https://doi.org/10.1007/s10853-014-8375-0