Young's Modulus Parallel to the Grain in Wood as A Function of Strain Rate, Stress Level and Mode of Loading
Keywords:
Tsuga heterophylla, Quercus sp., Pseudotsuga menziesii, dynamic tests, static tests, bending tests, compression tests, tension testsAbstract
Moduli of elasticity were determined parallel to the grain in wood specimens using dynamic flexural tests, static tensile tests, and static compression tests. in the static tests the specimens were repetitively loaded at different strain rates below their proportional limits. Stress rate and strain rate data were taken at discrete stress levels. Species used were red oak, Douglas-fir, and western hemlock.
Stress rate plotted as a linear function of strain rate with zero intercept. The slopes of the plots were Young's moduli. For the majority of specimens, there were no significant differences between Young's moduli in tension and Young's moduli in compression. There were also no indications that Young's moduli were either a function of stress level or strain rate. Dynamic flexural moduli uncorrected for shear deflection averaged 3% less than static tensile moduli.
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