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111.
V. I. Fabrikant 《Archive of Applied Mechanics (Ingenieur Archiv)》2001,71(6-7):371-388
Summary The following mixed boundary-value problem for a transversely isotropic elastic half-space is considered. Arbitrary tangential
displacements are prescribed at the exterior of a circle, while the interior of the circle is free of tangential stress, and
the normal stress vanishes all over the boundary. The governing integral equation is solved exactly, in closed form, and in
terms of elementary functions. The method of continuation of solutions previously published by the author has been used here.
Several examples are considered. No similar results has been reported before, even in the case of an isotropic body.
Received 8 May 2000; accepted for publication 20 July 2000 相似文献
112.
We provide a global existence result for the time-continuous elastoplasticity problem using the energetic formulation. For
this, we show that the geometric nonlinearities arising from the multiplicative decomposition of the strain can be controlled
via polyconvexity and a priori stress bounds in terms of the energy density. While temporal oscillations are controlled via
energy dissipation, the spatial compactness is obtained via regularizing terms involving gradients of the internal variables.
Dedicated to Sir John Ball on the occasion of his 60th birthday. 相似文献
113.
The dynamical behavior of multi-spot solutions in a two-dimensional domain Ω is analyzed for the two-component Schnakenburg
reaction–diffusion model in the singularly perturbed limit of small diffusivity ε for one of the two components. In the limit ε→0, a quasi-equilibrium spot pattern in the region away from the spots is constructed by representing each localized spot
as a logarithmic singularity of unknown strength S
j
for j=1,…,K at unknown spot locations x
j
∈Ω for j=1,…,K. A formal asymptotic analysis, which has the effect of summing infinite logarithmic series in powers of −1/log ε, is then used to derive an ODE differential algebraic system (DAE) for the collective coordinates S
j
and x
j
for j=1,…,K, which characterizes the slow dynamics of a spot pattern. This DAE system involves the Neumann Green’s function for the Laplacian.
By numerically examining the stability thresholds for a single spot solution, a specific criterion in terms of the source
strengths S
j
, for j=1,…,K, is then formulated to theoretically predict the initiation of a spot-splitting event. The analytical theory is illustrated
for spot patterns in the unit disk and the unit square, and is compared with full numerical results computed directly from
the Schnakenburg model.
相似文献
114.
The theory of fluid surfaces with elastic resistance to bending is applied to coexistent phase equilibria in biomembranes
composed of lipid bilayers. A simplified version of the model is used to simulate the necking and budding of closed vesicles.
相似文献
115.
C. Barentin P. Muller C. Ybert J.-F. Joanny J.-M. di Meglio 《The European physical journal. E, Soft matter》2000,2(2):153-159
The surface shear viscosity of monolayers formed at the surface of water by adsorbed polyethyl- eneoxyde and by stearic acid
is measured as a function of the surface pressure of the monolayer using a new surface viscometer. The principle of the viscometer
is the measurement of the drag force on a circular disk undergoing a uniform translation at the water surface: a hydrodynamic
model based on the lubrication approximation allows a calculation of the surface viscosities from the absolute measurement
of the drag forces.
Received: 26 August 1999 相似文献
116.
Mauricio Bogoya 《Journal of Mathematical Analysis and Applications》2008,344(2):601-615
We study the initial-value problem for a nonlocal nonlinear diffusion operator which is analogous to the porous medium equation, in the whole RN, N?1, or in a bounded smooth domain with Neumann or Dirichlet boundary conditions. First, we prove the existence, uniqueness and the validity of a comparison principle for solutions of these problems. In RN we show that if initial data is bounded and compactly supported, then the solutions is compactly supported for all positive time t, this implies the existence of a free boundary. Concerning the Neumann problem, we prove that the asymptotic behavior of the solutions as t→∞, they converge to the mean value of the initial data. For the Dirichlet problem we prove that the asymptotic behavior of the solutions as t→∞, they converge to zero. 相似文献
117.
Mikhail A. Vorotyntsev 《Physics and Chemistry of Liquids》2017,55(2):141-152
Ion solvation process has been analysed for the spherically symmetrical system where an ion is located inside a cavity surrounded by an isotropic nonlocal dielectric medium. It has been proven that for any dielectric properties of the medium, the electric field outside the cavity as well as the ion solvation energy depend only on the total ion charge but not of the particular distribution of the ion charge density inside the cavity. These characteristics remain unchanged if the charge is displaced from the external boundary of the cavity into it. Analytical formulas for them have been derived for a particular model of the nonlocal dielectric function. Comparison of results for the solvation energy on the basis of this new theory and of the conventional approach (disregarding the existence of the cavity) shows a significant difference between their predictions if the ion charge is displaced inside the ion cavity. 相似文献
118.
《Journal of computational chemistry》2017,38(5):257-264
Two alternative approaches for the quantum‐mechanical calculation of the nuclear‐relaxation term of elastic and piezoelectric tensors of crystalline materials are illustrated and their computational aspects discussed: (i) a numerical approach based on the geometry optimization of atomic positions at strained lattice configurations and (ii) a quasi‐analytical approach based on the evaluation of the force‐ and displacement‐response internal‐strain tensors as combined with the interatomic force‐constant matrix. The two schemes are compared both as regards their computational accuracy and performance. The latter approach, not being affected by the many numerical parameters and procedures of a typical quasi‐Newton geometry optimizer, constitutes a more reliable and robust mean to the evaluation of such properties, at a reduced computational cost for most crystalline systems. © 2016 Wiley Periodicals, Inc. 相似文献
119.
This paper reports on geometry dependent viscosity curves of the biaxial thermotropic LC-Polymer Vectra B 950 measured with rectangular slit dies. The geometry dependence of the flow behaviour originates from the flow of two layers. The layer near the wall is highly flow oriented and free from defects. The layer in the bulk has an ordered texture. The thickness of the wall layer decreases with wall shear stress. Based on the Frank theory and the assumption that the core of a moving disclination is the smallest radius of distortion, the wall layer thickness is predicted and compared with experimental data. 相似文献
120.