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Journal of Wood Science

Official Journal of the Japan Wood Research Society

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Mechanical stress grading of tropical timbers without regard to species

Journal of Wood Science volume 51, pages 339–347 (2005)Cite this article

Abstract

Some reports have shown that for single species the correlation between modulus of elasticity (MOE) and modulus of rupture (MOR) in bending is quite high. Tropical timbers consist of hundreds of species that are difficult to identify. This report deals with the mechanical stress grading of tropical timber regardless of species. Nine timber species or groups of species with a total number of 1094 pieces measuring 60 × 120 × 3000 mm, were tested in static bending. The MOE was measured flat wise, while MOR was tested edge wise. Statistical analysis of linear regression with a dummy model and analysis of covariance were used to analyze the role of MOE and the effect of species on prediction of MOR. The analysis showed that using MOE as a single predictor caused under/overestimation for one or more species and/or groups of species. The accuracy of prediction would be increased with species identification. An allowable stress and reference resistance for species and/or groups of species were provided to compare with the prediction of strength through timber grading. The timber strength class for species and/or groups of species was also established to support the application of mechanical timber grading.

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Authors and Affiliations

  1. Research Institute For Human Settlements, Jl. Panyaungan-Cileunyi Wetan, Bandung, 40008, Indonesia

    Anita Firmanti

  2. Faculty of Forestry, Bogor Agriculture University, Kompleks IPB Darmaga Bogor 16680, Indonesia

    Efendi Tri Bachtiar & Surjono Surjokusumo

  3. Research Institute for Sustainable Humanosphere, Kyoto University, Uji, 611-0011, Japan

    Kohei Komatsu & Shuichi Kawai

Authors
  1. Anita Firmanti
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  2. Efendi Tri Bachtiar
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  3. Surjono Surjokusumo
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  4. Kohei Komatsu
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  5. Shuichi Kawai
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Corresponding author

Correspondence to Shuichi Kawai.

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Firmanti, A., Bachtiar, E., Surjokusumo, S. et al. Mechanical stress grading of tropical timbers without regard to species. J Wood Sci 51, 339–347 (2005). https://doi.org/10.1007/s10086-004-0661-z

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  • DOI: https://doi.org/10.1007/s10086-004-0661-z

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