Estimating Young’s Modulus and Modulus of Rupture of Coconut Logs using Reconstruction Method

Authors

  • Bahtiar E.T. Forest Products Department, Bogor Agricultural University
  • Nugroho N. Forest Products Department, Bogor Agricultural University
  • Surjokusumo S. Civil Engineering Department, Pakuan University, Bogor

DOI:

https://doi.org/10.9744/ced.12.2.65-72

Keywords:

coconut logs, modulus of rupture (SR), reconstruction methods, Young’s modulus (E).

Abstract

This research develops a theory of the so called reconstruction method to estimate the Young’s modulus (E) and modulus of rupture (SR) of coconut logs. The reconstruction method includes among others; flexure test on small-clear specimens, which were taken from locations distributed along the horizontal as well as vertical direction inside the logs. Further, the estimated E and SR were acquired by arranging systematically each of the small clear specimens as if back in the original location in the logs. The estimation was assisted by mechanical theory, statistics (best fit multiple regression equations), mathematics (calculus), and geometry approach. This reconstruction method successfully estimates E and SR of the coconut logs. The average estimated E and SR value as acquired from tree sample number 1 and 2 were 8,118– 8,596 MPa, and 118–124 MPa, respectively. Those two values were still comparable to common US wood species used for construction i.e. 6,660–15,000 MPa (for E); and 58–132 MPa (for SR). Moreover those estimations of E and SR correlated significantly with each other. This again strengthens the reliability and representativeness of the E and SR values for coconut logs as acquired using the proposed reconstruction methods.

References

Biro Pusat Statistik, Statistik Indonesia 2002, Jakarta, 2002.

Kloot, N.H., Mechanical and Physical Properties of Coconut Palm, Australian Journal of Applied Science, 3 (4), 1952, pp. 293–323.

Meylan, B.A., Density Variation Within Cocos Nucifera Stems, New Zealand Journal of Forestry Science, 8(3), 1978, pp. 369–383.

Ghose, M. and Johri, B.M., Anatomy of Stems of Seedling Palms, Proceedings of the Indian Academy of Science, Plant Sciences, 100(4), 1990, pp. 215–223.

Aragon, C.T., Coconut Program Area Research Planning and Prioritization, Philipine Institute for Developments Studies, Los Banos, Phillipines, 2000.

Tomlinson, P.B., The Uniquenes of Palms, Botanical Journal of the Linnean Society, 151, 2005, pp. 4–14.

Rahayu, I.S., Sifat Fisik, Mekanis, serta Keawetan Batang Kelapa Hibrida (Physical and Mechanical Properties, and Durability of Hybrid Coconut Wood), Journal Ilmu Pertanian Indonesia, 2 (1), 2006, pp. 24-30.

Wardhani, I.Y., Kajian Sifat Dasar Kayu Kelapa (Coconut Wood Properties), Dissertation, Bogor Agricultural University, Bogor, 2005.

American Society for Testing and Material, Standard Practice for Establishing Structural Grades and Related Allowable Properties for Visually Graded Lumber, Designation D245–00, Philadelphia, PA, 2005.

American Society for Testing and Material, Standards Test Methods for Small Clear Specimen of Timber, Designation D143–94, Philadelphia, PA, 2005.

Bodig, J. and Jayne, B.A., Mechanics of Wood and Wood Composites, Van Nostrand Reinhold Company, USA, 1982.

Forest Products Laboratory, Wood Handbook: Wood as Engineering Material, Forest Products Laboratory USDA Forest Service Agricultural, 1999.

Tsoumist, J.D., Science and Technology of Wood: Structure, Properties, and Uses, Van Nostrand Reinhold, New York, 1993.

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Published

2010-08-26

How to Cite

E.T., B., N., N., & S., S. (2010). Estimating Young’s Modulus and Modulus of Rupture of Coconut Logs using Reconstruction Method. Civil Engineering Dimension, 12(2), 65-72. https://doi.org/10.9744/ced.12.2.65-72