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Effects of Span-to-depth Ratio and Poisson's Ratio on Elastic Constants from Bending and Plate Tests

  • Jeong, Gi Young (Department of Wood Science and Engineering, Research Institute for Agriculture & Life Science, Chonnam National University) ;
  • Kong, Jin Hyuk (Department of Wood Science and Engineering, Research Institute for Agriculture & Life Science, Chonnam National University)
  • Received : 2014.12.18
  • Accepted : 2015.02.09
  • Published : 2015.03.25

Abstract

The goal of this study is to evaluate the limitation of ASTM D 198 bending and ASTM D 3044 in determination of elastic modulus and shear modulus. Different material properties and span to depth ratios were used to analyze the effects of material property and testing conditions. The ratio of true elastic modulus to apparent elastic modulus evaluated from ASTM D 198 bending sharply decreased with increment of span to depth ratio. Shear modulus evaluated from ASTM D 198 bending decreased with increment of depth, whereas shear modulus evaluated from ASTM D 3044 was hardly influenced by increment of depth. Poisson's ratio influenced shear modulus from ASTM D 198 bending but did not influence shear modulus from ASTM D 3044. Different shearing factor was obtained for different depths of beams to correct shear modulus obtained from ASTM D 198 bending equivalent to shear modulus from theory of elasticity. Equivalent shear modulus of materials could be obtained by applying different shearing factors associated with beam depth for ASTM D 198 bending and correction factor for ASTM D 3044.

Acknowledgement

Supported by : Korea Forest Service

References

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