Выпуск: 1 , Том: 28 , Год издания: 2009

Summary: We propose a mathematical formalism of introducing attenuation in Schoenberg's Linear Slip model. This formalism consists in replacing the real-valued weaknesses, normal and tangential, entering in the stiffness matrix by the complex-valued quantities. To test the validity of this procedure, an ultrasonic experiment was performed with the use of a plate-stack model made from plexiglass plates. We measured velocities and attenuations of P-, SH- and SV-wave versus the angle between the ray and the symmetry axis of TI model for air-filled and oil-saturated state of the model under uniaxial pressure of 2 and 4 MPa. The data on velocities and attenuations were fitted by the derived theoretical functions. We have estimated the values of the imaginary and real parts of the complex-valued weaknesses. The real parts of the weaknesses are threefold for the air-filled model in comparison with the oil-saturated one. The imaginary parts of the weaknesses, responsible for attenuation, are one order of magnitude less than the values of the real parts of the weaknesses. Both P-wave anisotropies, the velocity anisotropy and the attenuation anisotropy, are greater in the air-filled model than in the oil-saturated one. Besides, in the air-filled model, the symmetry-axis attenuation of the P-wave is much greater than the S-wave symmetry-axis attenuation, whereas in the oil-saturated model these attenuations are similar.