English
Related papers

Related papers: On the Backus average of layers with randomly orie…

200 papers

In general, the Backus average of an inhomogeneous stack of isotropic layers is a transversely isotropic medium. Herein, we examine a relation between this inhomogeneity and the strength of resulting anisotropy, and show that, in general,…

Geophysics · Physics 2020-12-08 Filip P. Adamus , Ayiaz Kaderali , Michael A. Slawinski , Theodore Stanoev

In this paper, following the Backus (1962) approach, we examine expressions for elasticity parameters of a homogeneous generally anisotropic medium that is long-wave-equivalent to a stack of thin generally anisotropic layers. These…

Geophysics · Physics 2016-06-23 Len Bos , David R. Dalton , Michael A. Slawinski , Theodore Stanoev

Backus (1962) developed his technique for homogenization of a layered structure solely within the context of linear elastic theory. In this paper we propose an extended use of Backus average for finitely deformed materials of a layered…

Classical Physics · Physics 2019-11-28 Andrey Melnikov

We examine the Backus average of a stack of isotropic layers overlying an isotropic halfspace to examine its applicability for the quasi-Rayleigh and Love wave dispersion curves, both of which apply to the same model. We compare these…

Geophysics · Physics 2019-09-04 David R. Dalton , Thomas B. Meehan , Michael A. Slawinski

The anisotropy of an equivalent medium resulting from the Backus (1962) average is induced by the vertical inhomogeneity among its constituent layers. The velocity field of the constituent isotropic layers increases linearly with depth,…

Geophysics · Physics 2019-06-26 Md Abu Sayed , Theodore Stanoev

In this paper, we discuss five parameters that indicate the inhomogeneity of a stack of parallel isotropic layers. We show that, in certain situations, they provide further insight into the intrinsic inhomogeneity of a Backus medium, as…

Geophysics · Physics 2020-12-04 Filip P. Adamus , Ayiaz Kaderali

Elastic anisotropy might be a combined effect of the intrinsic anisotropy and the anisotropy induced by thin-layering. The Backus average, a useful mathematical tool, allows us to describe such an effect quantitatively. The results are…

Geophysics · Physics 2021-01-08 Filip P. Adamus

We show that, in general, the translational average over a spatial variable---discussed by Backus \cite{backus}, and referred to as the equivalent-medium average---and the rotational average over a symmetry group at a point---discussed by…

Geophysics · Physics 2017-12-20 Len Bos , David R. Dalton , Michael A. Slawinski

In this paper, we consider a long-wave equivalent medium to a finely parallel-layered inhomogeneous medium, obtained using the Backus average. Following the work of Postma and Backus, we show explicitly the derivations of the conditions to…

Geophysics · Physics 2018-09-28 F. P. Adamus

We show that the Backus (1962) equivalent-medium average, which is an average over a spatial variable, and the Gazis et al. (1963) effective-medium average, which is an average over a symmetry group, do not commute, in general. They commute…

Geophysics · Physics 2016-01-13 David R. Dalton , Michael A. Slawinski

In this paper, we continue the study of Bos et al. (2018) regarding statistical and numerical considerations of the Backus (1962) product approximation. While the approximation is typically quite good for seismological scenarios, Bos et al.…

Geophysics · Physics 2020-12-07 Ayiaz Kaderali , Izabela Kudela , Theodore Stanoev

The deformation problem for a transversely isotropic elastic layer bonded to a rigid substrate and coated with a very thin elastic layer made of another transversely isotropic material is considered. The leading-order asymptotic models (for…

Analysis of PDEs · Mathematics 2015-04-28 Ivan Argatov , Gennady Mishuris

Dalton and Slawinski (2016) show that, in general, the Backus (1962) average and the Gazis et al. (1963) average do not commute. Herein, we examine the extent of this noncommutativity. We illustrate numerically that the extent of…

Geophysics · Physics 2016-09-06 David R. Dalton , Michael A. Slawinski

In this paper, we examine the applicability of the approximation, $\overline{f\,g}\approx \overline f\,\overline g\,$, within Backus (1962) averaging. This approximation is a crucial step in the method proposed by Backus (1962), which is…

Geophysics · Physics 2019-01-01 Len Bos , Tomasz Danek , Michael A. Slawinski , Theodore Stanoev

We develop a model for the reflection and transmission of plane waves by an isotropic layer sandwiched between two uniaxial crystals of arbitrary orientation. In the laboratory frame, reflection and transmission coefficients corresponding…

Materials Science · Physics 2009-04-29 Erik S. Thomson , Larry A. Wilen , John S. Wettlaufer

The modelling of off-axis simple tension experiments on transversely isotropic nonlinearly elastic materials is considered. A testing protocol is proposed where normal force is applied to one edge of a rectangular specimen with the opposite…

Soft Condensed Matter · Physics 2020-09-07 Michel Destrade , Brian Mac Donald , Jerry Murphy , Giuseppe Saccomandi

Stacking is a widely used model averaging technique that asymptotically yields optimal predictions among linear averages. We show that stacking is most effective when model predictive performance is heterogeneous in inputs, and we can…

Methodology · Statistics 2021-10-29 Yuling Yao , Gregor Pirš , Aki Vehtari , Andrew Gelman

Anisotropic light transport is extremely common among scattering materials, yet a comprehensive picture of how macroscopic diffusion is determined by microscopic tensor scattering coefficients is not fully established yet. In this work, we…

Randomly textured polycrystalline materials of constituents with highly anisotropic nature of grains can be considered globally isotropic. In order to determine the isotropic properties, like elasticity or conductivity, we propose a theory…

Materials Science · Physics 2018-12-07 Adam Takacs , Géza Tichy , Péter Dusán Ispánovity

We discuss several physical constraints imposed on elasticity parameters of a transversely isotropic (TI) tensor. There are three types of restrictions we investigate; a fundamental one of stability conditions, and two additional ones,…

Geophysics · Physics 2019-04-04 Filip P. Adamus , Izabela Kudela
‹ Prev 1 2 3 10 Next ›