Notice of Retraction: Experimental research on different propagation velocity of stress wave in poplar and larch logs

Abstract

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