Influence of Moisture Content on Longitudinal, Radial, and Tangential Ultrasonic Velocity for Two Brazilian Wood Species

Authors

  • Raquel Gon¸alves
  • Odilon Antonio Leme da Costa

Keywords:

Stiffness terms, fiber saturation point, effective density

Abstract

The effects of MC on longitudinal, radial, and tangential ultrasonic wave velocity and on the respective terms of the stiffness matrix were examined for Brazilian pine (Araucaria angustifolia) and cupińba (Goupia glabra). The ultrasonic wave velocity tended to increase with a decrease in MC, and the effect of MC on the ultrasonic wave velocity below the FSP was greater than above. Below the FSP, the stiffness terms tended to decrease with increasing MC, but above the FSP, they increased with increasing MC because of the influence of water on the bulk density. This result may be corrected by using the effective density above FSP, which depends on the mobility of free water and differs for the two species.

References

Bucur V (2006) Acoustics of wood. CRC Press, Inc. 284 pp.nGerhards C (1982) Effect of moisture content and temperature on mechanical properties of wood. An analysis of immediate effects. Wood Fiber Sci 14(1):4-36.nMishiro A (1996a) Ultrasonic velocity and average moisture content in wood II. Mokuzai Gakkaishi 42(10):612-617.nMishiro A (1996b) Ultrasonic velocity and average moisture content in wood III. Mokuzai Gakkaishi 42(10):930-936.nSobue N (1993) Simulation study on stress wave velocity in wood above fiber saturation point. Mokuzai Gakkaishi 39(3):271-276.nWang S, Chiu C, Lin C (2002) Variations in ultrasonic wave velocity and dynamic Young's modulus with moisture content for Taiwania plantation lumber. Wood Fiber Sci 34(3):370-381.n

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Published

2008-11-03

Issue

Number 4 / October 2008

Section

Research Contributions

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