Abstract:

The experiments to poplar and larch logs samplings were done by using stress wave testing instrument. The relationships among radial, tangential and longitudinal (heartwood and sapwood) propagation velocity of stress wave in the two logs samplings were studied. Meanwhile the relations were analyzed between radial velocity and diameter, as well as tangential velocity and the detection angles. The results indicated that, in the both species, the radial velocity of stress wave had positive correlation with the diameter, and that the longitudinal propagation velocity in the sapwood was larger than that in the corresponding heartwood, and that tangential velocity had a quadratic function relation with the detection angle. In addition, the paper showed the ratio thresholds between longitudinal velocity in heartwood and sapwood and radial speed separately.

Key words: Populus, Larix, logs, stress wave, propagation velocity