Stress wave propagation modeling in wood non-destructive testing

In the stress wave based nondestructive testing methods for quality assessment of wood, the propagation characters of the stress wave play an important role for the efficiency and accuracy of nondestructive testing technique. To model the transmitting behaviors, the propagation of stress wave in the anisotropic elastic media as wood was studied according to the mechanical wave theory in solid. The governing equation of stress wave propagation in wood was given in cylindrical polar coordinates, and the equations of the three components of the displacement vector were presented. The solutions of the equations were proposed in axisymmetric motions. The elastic constants of the pine are given, the stress wave propagation in both axisymmetric and non-axixymmetric conditions is discussed at the end.