Tengiz Buchukuri, Roland Duduchava

Thin Shells with Lipschitz Boundary

abstract:
In [58], we have revised an asymptotic model of a shell (Koiter, Sanchez-Palencia, Ciarlet, etc.), based on the the calculus of tangent Günter's derivatives, developed in the papers of R. Duduchava, D. Mitrea and M. Mitrea  [55,58,64]. As a result, the 2-dimensional shell equation on a mid-surface $\mathcal{S}$ was written in terms of Günter's derivatives, unit normal vector field and the Lamé constants. The principal part of the obtained equation coincides with the Lamé equation on the Hypersurface $\mathcal{S}$ investigated in  [55,58,64].

The present investigation is inspired by the paper of G. Friesecke, R. D. James and S. Müller  [77], where a hierarchy of Plate Models are derived from nonlinear elasticity by $\Gamma$-Convergence. The final goal of the present investigation is to derive and investigate 2D shell equations in terms of Günter's derivatives by $\Gamma$-Convergence.

As a first step to the final goal, by T. Buchukuri, R. Duduchava and G. Tephnadze was studied a mixed boundary value problem for the stationary heat transfer equation in a thin layer around a surface $\mathcal{C}$ with the boundary (see [16]). It was established what happens to the solution of the boundary value problem when the thickness of the layer converges to zero. In particular, there was shown that the $\Gamma$-limit of a mixed type Dirichlet-Neumann boundary value problem (BVP) for the Laplace equation in the initial thin layer is a Dirichlet BVP for the Laplace-Beltrami equation on the surface. The result was derived based on the variational reformulation of the problem using the Günter's tangent differential operators on a hypersurface and layers. The similar results were obtained for the Lamé operator. This approach allows global representation of basic differential operators and of corresponding boundary value problems in terms of the standard cartesian coordinates of the ambient Euclidean space $\mathbb{R}^n$.

Mathematics Subject Classification: 35J05, 35J20, 53A05, 80A20

Key words and phrases: Hypersurface, Günter's derivatives, Lamé equation, $\Gamma$-Convergence, Shell equation