Journal of the Korean Wood Science and Technology

The Korean Society of Wood Science & Technology (한국목재공학회)
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Effect of Test Zone Selection for Evaluating Bending Strength of Lumber

  • Pang, Sung-Jun (Dept. of Forest Sciences, College of Agriculture & Life Sciences, Seoul National University) ;
  • Lee, Jun-Jae (Dept. of Forest Sciences, Research Institute for Agriculture and Life Sciences, College of Agriculture & Life Sciences, Seoul National University) ;
  • Oh, Jung-Kwon (Dept. of Forest Sciences, Research Institute for Agriculture and Life Sciences, College of Agriculture & Life Sciences, Seoul National University)
  • Received : 2013.06.18
  • Accepted : 2013.09.24
  • Published : 2013.09.25
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Abstract

This study investigated the effect of test zone selection for evaluating bending strength of visually graded lumber. This will contribute to the understanding of two different methods under different standards. In method I, the major defect was randomly placed in the test specimen. In method II, the major defect was randomly placed in the maximum moment zone (MMZ). The results showed that the method II is more accurate for reflecting the effect of defects governing the grade of lumber. Unless the maximum strength-reducing defect (MSRD) is placed in MMZ, the evaluated value would be higher than that of MSRD. For evaluating the modulus of rupture (MOR) of visually graded lumber in test set-up of Method I, the Eq. (5) needs to be considered.

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References

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Cited by

  1. Determination of Grades and Design Strengths of Machine Graded Lumber in Korea vol.43, pp.4, 2015, https://doi.org/10.5658/WOOD.2015.43.4.446
  2. Analysis of Allowable Stresses of Machine Graded Lumber in Korea vol.43, pp.4, 2015, https://doi.org/10.5658/WOOD.2015.43.4.456