Nondestructive Evaluation of Bending Strength Performances for Red Pine Containing Knots Using Flexural Vibration Techniques

  • Byeon, Hee-Seop (College of Agriculture & Life Science, Institute of Agriculture & Life Science, Gyeongsang National University) ;
  • Ahn, Sang-Yeol (Hansol Homedeco. Co., Ltd., Flooring R&D Institute) ;
  • Park, Han-Min (College of Agriculture & Life Science, Institute of Agriculture & Life Science, Gyeongsang National University)
  • Received : 2005.05.06
  • Accepted : 2005.08.25
  • Published : 2005.09.25


This paper deals with flexural vibration techniques as a means of predicting bending strength properties for quarter-sawn and flat-sawn planes of red pine containing knots. Dynamic modulus of elasticity $(MOE_d)$ was calculated from resonance frequency obtained from the flexural vibration induced by a magnetic driver in quarter-sawn and flat-sawn planes of red pine containing knots. The dynamic MOE were well correlated to bending strength properties. Their correlation coefficients ranged from 0.866 to 0.800 for the regression between dynamic MOE and static bending MOE or MOR. The difference of the values between quarter-sawn and flat-sawn was very small. These values were higher than correlation between percentage of total knot diameter to total width of red pine specimen $(K_T(%))$ as well as $K_O(%)$ base upon ASTM D 3737 and static bending strength properties (correlation coefficient r = 0.448~0.704), and were similar to those between static bending MOE and bending MOR (r = 0.850). These results indicate that dynamic MOE obtained from resonance frequency induced by flexural vibration of magnetic driver is able to effectively use for predicting of static bending strength of red pine containing knots as well as static MOE.



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