Wood Failure Under Torsional Loading as A Function of Temperature
Keywords:Wood failure, temperature, red spruce, balsam fir, torsion
Cylindrical wood bars were twisted through a 360-degree rotation in a standard torsiometer in glycerine at 20, 60, 100, and 140 C temperatures. The torsional load-deformation curves were plotted for each specimen, and the strain and stress values were calculated at each temperature. The failure zones were studied by light and electron microscopic techniques.
It was found that failure occurs in the radial plane of wood, mostly in the outer region of the bar, as a result of torsional shear stresses acting in the same plane. The temperature dependence of torsional strain is expressed in the form of a characteristic curve, the peak value falling at 100 C and the high rate increase occurring in the range 20-100 C.
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