INFLUENCE OF THERMAL SOFTENING AND DEGRADATION ON THE RADIAL COMPRESSION BEHAVIOR OF WET SPRUCE

Thermal softening and degradation of wood are important factors in woo d processing. In this investigation, the influence of temperature - be tween 0 and 200 degrees C - on the mechanical behavior of wet spruce s ubjected to large radial compression was studied. The yield stress of wet spruce dropped by slightly less than one tenth between 0 and 200 d egrees C. The glass transition of lignin was detected accurately by me asuring the yield stress. A thermal degradation process was observed b etween 150 and 200 degrees C. The shapes of the normalized stress-stra in curves were similar at different temperatures.