Elastodynamic analysis of an anisotropic liquid-saturated porous medium is made to study a deformation problem of a transversely isotropic liquid-saturated porous medium due to mechanical sources. Certain physical pro...Elastodynamic analysis of an anisotropic liquid-saturated porous medium is made to study a deformation problem of a transversely isotropic liquid-saturated porous medium due to mechanical sources. Certain physical problems are of the nature, in which the deformation takes place only in one direction, e.g., the problem relating to deformed structures and columns. In soil mechanics, an assumption of only vertical subsidence is often invoked and this leads to the one dimensional model of poroelasticity. By consid- ering a model of one-dimensional deformation of the anisotropic liquid-saturated porous medium, variations in disturbances are observed with reference to time and distance. The distributions of displacements and stresses are affected due to the anisotropy of the medium, and also due to the type of sources causing the disturbances.展开更多
The acoustic signal from an impulsive source near an ideal rigid wedge consists of the reflected waves from the inclined plane and the diffracted waves from the apex of the wedge. There are two theoretical solutions o...The acoustic signal from an impulsive source near an ideal rigid wedge consists of the reflected waves from the inclined plane and the diffracted waves from the apex of the wedge. There are two theoretical solutions of the problem. The first was obtained by Biot-Tolstoy using normal coordinates. The second was Trorey's Helmholtz-Kirchhoff solution. So far the experimental measurements have concentrated on the diffracted wave from the wedge apex and ignored the rest of the solution. The Biot-Tolstoy exact wedge solution is used in this paper to study the sound transmission in wedges of angle 12 °and 52 °approximately. The theory and the experiments are consistent. Also studied is the behaviour of the reflected and diffracted waves from a 270 °wedge. Both theories predicted the existence a specular ' image ' reflection when a coincident source and receiver are over a half plane. The experimental results showed that the Biot-Tolstoy theory was accurate and the Trorey solution produced quite large errors.展开更多
文摘Elastodynamic analysis of an anisotropic liquid-saturated porous medium is made to study a deformation problem of a transversely isotropic liquid-saturated porous medium due to mechanical sources. Certain physical problems are of the nature, in which the deformation takes place only in one direction, e.g., the problem relating to deformed structures and columns. In soil mechanics, an assumption of only vertical subsidence is often invoked and this leads to the one dimensional model of poroelasticity. By consid- ering a model of one-dimensional deformation of the anisotropic liquid-saturated porous medium, variations in disturbances are observed with reference to time and distance. The distributions of displacements and stresses are affected due to the anisotropy of the medium, and also due to the type of sources causing the disturbances.
文摘The acoustic signal from an impulsive source near an ideal rigid wedge consists of the reflected waves from the inclined plane and the diffracted waves from the apex of the wedge. There are two theoretical solutions of the problem. The first was obtained by Biot-Tolstoy using normal coordinates. The second was Trorey's Helmholtz-Kirchhoff solution. So far the experimental measurements have concentrated on the diffracted wave from the wedge apex and ignored the rest of the solution. The Biot-Tolstoy exact wedge solution is used in this paper to study the sound transmission in wedges of angle 12 °and 52 °approximately. The theory and the experiments are consistent. Also studied is the behaviour of the reflected and diffracted waves from a 270 °wedge. Both theories predicted the existence a specular ' image ' reflection when a coincident source and receiver are over a half plane. The experimental results showed that the Biot-Tolstoy theory was accurate and the Trorey solution produced quite large errors.
