Analysis of Wood Laminated Beams Reinforced by Natural Fibres

Abstract:

This paper presents an analysis on the viability of the use of natural fibres, in particular sisal fibres, as a reinforcing material in wood laminate structures. The use of natural fibres associated to the manufacturing of beams, with wood from reforestation, is in accordance with the current economic interest and ecological appeal. Sisal fibres have attracted attention for presenting adequate mechanical characteristics for such application. The laminated beams used in this research were constituted by Pinus sp and were reinforced by sisal strips with a thickness of 2 mm glued by Epoxi adhesive on bottom of the beam on the tensile region. Each lamina had the following dimensions: width of 50 mm, height of 20 mm and the length of the beam is 1.5 m. For the theoretical analysis of wood laminate beams three models: stress functions, classical lamination theory and section transformed method are carried out. It was noted that the average differences between the theoretical results and experimental data are given by: 11% and 2 % for normal and shear stresses respectively, and around 8%, for displacements. As a conclusion, the strengthening of wood laminate beams with sisal fibres is effective in wood structural elements, in which the elastic modulus is at maximum equal to these fibres and also prevents fragile failure on critical tensile region.

• Periodical: Advanced Materials Research (Volume 778)
• Pages: 553-560
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.778.553
• Online since: September 2013
• Authors: Nilson Tadeu Mascia, Raul Martini Mayer
• Keywords: Bending Tests, Laminated Beams, Natural Fiber, Reinforcement, Sisal Fiber, Wood

References

[1] J. Bodig, B.A. Jayne, Mechanics of Wood and Wood Composites. Van Nostrand, New York (1982).

[2] A.K. Mohanty,M. Misra and L. T. Drzal, Natural fibers, biopymers and biocomposites. 1st edition Taylor & Francis Group, Boca Raton, Fl (2005).

[3] A.R. Martin, S. Manolache, F.S. Denes, L.H.C. Mattoso, Functionalization of Sisal fibres and high-density polyethylene by cold plasma treatment - Journal of Applied Polymer Science. 85(10), (2004) 2145-2154.

DOI: 10.1002/app.10801

[4] J.W. Freire and A. L. Beraldo, Technique and alternative materials for construction, Unicamp, Campinas, Brazil, (In Portuguese) (2003).

[5] S.G. Lekhnitskii, Theory of Elasticity of an Anisotropic Body. 1a ed. Moscou, Mir (1981).

[6] Z. Hashin, Plane anisotropic beams, Journal Applied Mechanics. Trans. of Asme, 257-262 (1967).

[7] R.M. Jones, Mechanics of composite materials. New York: Hemisphere (1975).

[8] ABNT NBR 7190: 1997 – Design for wood Structures (in portuguese). Rio de Janeiro, Brazil. 1997, 107p.

[9] N.T. Mascia, J.E. Furlani, L. Vanalli, Mechanical Analysis of Sisal Fibers to Use as a Reinforced Material in Wood Beams. Journal of Civil Engineering and Architecture, 4 (2010) (12): 1-7.