Bending and Creep Deformation of a Wood-Based Lightweight Panel: An Experimental Study

Authors

  • Jonaz Nilsson
  • Jimmy Johansson

Keywords:

Lightweight panel, bending, creep, deformation, rupture

Abstract

 

When wood exposed to long-term load, creep deformation can occur, because of its viscoelastic characteristic. The aim of this study was to increase the understanding and knowledge of creep deformation on a wood based lightweight panel of sandwich type, to see if this type of panel had similar properties for creep as solid wood has. This was done through a study based on experiments. The studied panel consisted of two face sheets of beech wood and a core of pine wood struts cross-glued to the face sheets. A solid beech panel was used as a reference. There were in all 27 samples of panel models; the densities of the lightweight panels varied from 165 to 297 kg/m3 compared with the solid panel of 705 kg/m3 density. The study consisted of two parts, a bending test and a creep test. The bending test was used to determine the maximum failure load for the panels. For the creep test, a 30% failure load was used. When the results from the bending tests were ranked to load capacity in relation to density, the results for the lightweight panel varied from 9.0 to 18.0 m4/s2, compared with the value of the reference panel at 27.3 m4/s2. This measured how effective the panel was in withstanding bending loads in relation to density. However, it did not say that the panel with the highest value also took the highest load in absolute terms. If the creep deformation is instead ranked in relation to density, the results for the lightweight panel varied from 10.4 kg/m to 33.7 kg/m. compared with the value of the reference panels at 45.5 kg/m. As with the bending tests, these values show a ranking of how effective the panels are to resist creep deformation in relation to density.

 


References

References

Alinia MM, Shakiba M, Habashi HR (2009) Shear failure characteristics of steel plate girders. Thin-Walled Structures 47(12): 1498-1506.

Araman PA, Gatchel CJ, Reynolds HW (1982) Meeting the solid wood needs of the furniture and cabinet industries: standard-size hardwood blanks. United States Department of Agriculture, Northeastern Forest Experiment Station, Forest Service, Research Paper NE-494.

Basha HS, Goel SC (1994) Seismic resistant truss moment frames with ductile vierendeel segment. Eleventh World Conference on Earthquake Engineering.

Clouser WS (1959) Report no. 2150, Creep of small wood beams under constant bending load, Madison, Wis.: US Dept. of Agriculture, Forest Service, Forest Products Laboratory.

Coleman BD, Noll W (1961) Foundations of linear viscoelasticity. Reviews of Modern Physics 33(2): 239.

Dinwoodie JM (2004) Timber: Its nature and behaviour. Second edition. Taylor & Francis e-Library. 253 pp.

Du Y, Yan N, Kortschot MT (2013) An experimental study of creep behavior of lightweight natural fiber-reinforced polymer composite/honeycomb core sandwich panels. Composite Structures 106: 160-166.

Gnanaharan R, Haygreen J (1979) Comparison of the creep behavior of a basswood waferboard to that of solid wood. Wood and Fiber Science 11(3): 155-170.

Goh SG, Junginger M, Cocchi M, Marchal D, Thrän D, Henning C, Heinimö J, Nikolaisen L, Schouwenberg PP, Bradley D, Hess R, Jacobson J, Ovard L, Deutmeyer M (2013) Wood pellet market and trade: a global perspective. Biofuels, Bioproducts and Biorefining 7(1): 24-42.

Holzer SM, Loferski JR, Dillard DA (1989) A review of creep in wood: concepts relevant to develop long-term behavior predictions for wood structures. Wood and Fiber Science 21(4): 376-392.

Haygreen J, Hall H, Yang KN, Sawicki R (1975) Studies of flexural creep behavior in particleboard under changing humidity conditions. Wood and Fiber Science 7(2): 74-90.

Huang Y (2016) Creep behavior of wood under cyclic moisture changes: interaction between load effect and moisture effect. Journal of wood science 62(5): 392-399.

Leichti RJ, Tang RC (1989) Effect of creep on the reliability of sawn lumber and wood-composite I-beams. Mathematical and Computer Modelling 12(2): 153-161.

Navi P, Stanzl-Tschegg S (2009) Micromechanics of creep and relaxation of wood. A review COST Action E35 2004–2008 wood machining–micromechanics and fracture. Holzforschung 63(2): 186-195.

Nilsson J, Ormarsson S, Johansson J (2017) Moisture-related distortion and damage of lightweight wood panels—experimental and numerical study. Journal of the Indian Academy of Wood Science: 1-11.

Puettmann ME, Wilson JB (2005) Life-cycle analysis of wood products Cradle-to-gate LCI of residential wood building materials. Wood and Fiber Science 37: 18-29.

Ratnasingam J (2003) A matter of design in the South East Asian wooden furniture industry. European Journal of Wood and Wood Products 61(2): 151-154.

Roylance D (2001) Engineering viscoelasticity. Department of Materials Science and Engineering–Massachusetts Institute of Technology, Cambridge MA 2139: 37pp.

Sandberg D, Johansson I (1995) Report Kvarstående deformation hos furu efter böjbelastning under samtidig fuktvariation. KTH Royal Institute of Technology. 8pp (Swedish).

Takahashi C, Ishimaru Y, Lida I, Furuta Y (2004) The creep of wood destabilized by change in moisture content. Part 1: The creep behaviors of wood during and immediately after drying. Holzforschung 58(3): 261-267.

Takahashi C, Ishimaru Y, Lida I, Furuta Y (2005) The creep of wood destabilized by change in moisture content. Part 2: The creep behaviors of wood during and immediately after adsorption. Holzforschung 59(1): 46-53.

Takahashi C, Ishimaru Y, Lida I, Furuta Y (2006) The creep of wood destabilized by change in moisture content. Part 3: The influence of changing moisture history on creep behavior. Holzforschung 60(3): 299-303.

Wood LW (1958) Report no. 2121, Sandwich panels for building construction. Madison, Wis.: US Dept. of Agriculture, Forest Service, Forest Products Laboratory.

Zirakian T, Showkati H (2006) Distortional buckling of castellated beams. Journal of Constructional Steel Research 62(9): 863-871.

Downloads

Published

2019-01-27

Issue

Section

Research Contributions