Abstract:

In order to study stress wave propagation velocities and those influencing factors in log's cross section, logs of Quercus mongolica , Pinus koraiensis , Abies nephrolepis and Populus ussuriensis were chosen as test materials to measure stress wave propagation velocities at different tangential angles. In addition, MATLAB was used to establish fitting models of stress wave propagation velocities and tangential angles. The results showed that nonlinear relationship existed between stress wave propagation velocities and tangential angles in log's cross section of Quercus mongolica, Pinus koraiensis , Abies nephrolepis and Populus ussuriensis. When tangential angles exceeded 36°, highest stress wave propagation velocities existed in log's cross section of Populus ussuriensis but lowest in log's cross section of Quercus mongolica . Finally, maximum velocities of in log's cross section of Quercus mongolica , Pinus koraiensis , Abies nephrolepis and Populus ussuriensis were 1 109.0, 1 220.4, 1 245.8, and 1 618.3 m ·s^-1, respectively.

Key words: stress wave, non-destructive evaluation, tangential angle, propagation velocities