排序方式: 共有40条查询结果,搜索用时 31 毫秒
1.
2.
Motivated by nonlinear elasticity theory, we study deformations that are approximately differentiable, orientation-preserving
and one-to-one almost everywhere, and in addition have finite surface energy. This surface energy E{\mathcal{E}} was used by the authors in a previous paper, and has connections with the theory of currents. In the present paper we prove
that E{\mathcal{E}} measures exactly the area of the surface created by the deformation. This is done through a proper definition of created surface, which is related to the set of discontinuity points of the inverse of the deformation. In doing so, we also obtain an SBV regularity result for the inverse. 相似文献
3.
4.
Isabel C. Henao Castañeda Carlos O. Della Védova Oscar E. Piro Nils Metzler-Nolte Jorge L. Jios 《Polyhedron》2010
Structural and conformational properties of S-benzyl ferrocenecarbothioate (I) and S-(2-methoxyphenyl) ferrocenecarbothioate (II) are analyzed using data obtained from X-ray diffraction, vibrational data and theoretical calculations. According to chemical quantum calculations, the synperiplanar and antiperiplanar forms are found as the first and second more stable conformations, respectively, for the title compounds. The geometric parameters and normal modes of vibration were calculated using a density functional theory method (B3LYP) and the 6-31+G∗∗ basis set for all atoms except for iron. For this atom the calculations were carried out with the Lanl2dz basis set. The calculated parameters are in good agreement with the corresponding X-ray diffraction values. The combined experimental and theoretical approach allows a consistent assignment for most of the fundamental modes. 相似文献
5.
Duvan Henao 《Journal of Elasticity》2009,94(1):55-68
We prove that energy minimizers for nonlinear elasticity in which cavitation is allowed only at a finite number of prescribed
flaw points can be obtained, in the limit as ε→0, by introducing micro-voids of radius ε in the domain at the prescribed locations and minimizing the energy without allowing for cavitation. This extends the result
by Sivaloganathan, Spector, and Tilakraj (SIAM J. Appl. Math. 66:736–757, 2006) to the case of multiple cavities, and constitutes a first step towards the numerical simulation of cavitation (in the nonradially-symmetric
case).
相似文献
6.
We consider the minimization of in a perforated domain of among maps that are incompressible (det ) and invertible, and satisfy a Dirichlet boundary condition u = g on ?Ω. If the volume enclosed by g (?Ω) is greater than |Ω|, any such deformation u is forced to map the small holes Bε( a i) onto macroscopically visible cavities (which do not disappear as ε → 0). We restrict our attention to the critical exponent p = n, where the energy required for cavitation is of the order of and the model is suited, therefore, for an asymptotic analysis (v1,…, vM denote the volumes of the cavities). In the spirit of the analysis of vortices in Ginzburg‐Landau theory, we obtain estimates for the “renormalized” energy showing its dependence on the size and the shape of the cavities, on the initial distance between the cavitation points a 1,…, a M, and on the distance from these points to the outer boundary ?Ω. Based on those estimates we conclude, for the case of two cavities, that either the cavities prefer to be spherical in shape and well separated, or to be very close to each other and appear as a single equivalent round cavity. This is in agreement with existing numerical simulations and is reminiscent of the interaction between cavities in the mechanism of ductile fracture by void growth and coalescence. © 2012 Wiley Periodicals, Inc. 相似文献
7.
J. K. Brooks Kazuyuki Saitô JD Maitland Wright 《Rendiconti del Circolo Matematico di Palermo》2003,52(1):5-14
LetA be aC*-algebra with second dualA″. Let (φ
n)(n=1,...) be a sequence in the dual ofA such that limφ
n(a) exists for eacha εA. In general, this does not imply that limφ
n(x) exists for eachx εA″. But if limφ
n(p) exists whenever p is the range projection of a positive self-adjoint element of the unit ball ofA, then it is shown that limφ
n(x) does exist for eachx inA″. This is a non-commutative generalisation of a celebrated theorem of Dieudonné. A new proof of Dieudonné’s theorem, for
positive measures, is given here. The proof of the main result makes use of Dieudonné’s original theorem. 相似文献
8.
9.
Jos Antonio Henao ngela Marcela Montao Leonor Y. Vargas‐Mndez Vladimir V. Kouznetsov Reinaldo Atencio 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(4):o228-o230
The title compound, C16H15N3, shows a hindrance effect between adjacent amino and methyl groups that leads to a structural distortion, which is reflected in the non‐planarity of the quinoline entity and in the bond angles and distances. The crystal packing consists of chains along the b axis sustained by an intermolecular hydrogen bond between the amino group and the N atom of the pyridyl ring. 相似文献
10.
In this paper, we present and analyze a variational model in nonlinear elasticity that allows for cavitation and fracture.
The main idea in unifying the theories of cavitation and fracture is to regard both cavities and cracks as phenomena of the
creation of a new surface. Accordingly, we define a functional that measures the area of the created surface. This functional
has relationships with the theory of Cartesian currents. We show that the boundedness of that functional implies sequential
weak continuity of the determinant of the deformation gradient, and that the weak limit of one-to-one almost everywhere deformations
is also one-to-one almost everywhere. We then use these results to obtain the existence of minimizers of variational models
that incorporate elastic energy and this created surface energy, taking into account orientation-preserving and non-interpenetration
conditions. 相似文献