Singular limits with geometric effects

University Of Pittsburgh, Pittsburgh PA

Investigators

Abstract

This award supports the ongoing research program of the Principal Investigator on the mathematical analysis of some problems arising in engineering and applied science, in particular involving fluids in thin domains and thin elastic structures. The Principal Investigator will combine techniques from several areas of mathematics to study certain engineering design problems. These problems are linked by their "singular limits" context and the fact that their solutions are tuned to a variable geometry setting or to a-posteriori obtained geometrical constraints. The topics that will be tackled fall into four categories: (1) dimension reduction in fluid dynamics (e.g., determining effective two-dimensional models for the behavior of a fluid in a thin domain), (2) modeling and analysis of the shape of a growing body (as in various contexts in biology), (3) rigidity and flexibility of elastic prestrained materials (as caused, for example, by inhomogeneous growth or swelling or shrinkage), (4) energy scaling regimes in elasto-plastic materials (for which deformations are irreversible beyond a certain point). The following analytical techniques will be investigated: (1) dimension reduction and homogenization of compressible Navier-Stokes equations using relative entropy and scaling of the Korn and the conformal Korn inequalities in thin domains, (2) a novel "controlled growth" model, due to A. Bressan, that couples the partial differential equation for the transport of morphogen-producing cells (in cellular biology) with two constrained minimization problems for the morphogen concentration and the growth velocity, (3) variational models in prestrained elasticity in the presence of the Monge-Ampere constraint without any a-priori assumption on the structure of its minimizers (such as convexity, higher regularity, or boundary conditions) studied using convex integration, (4) dimension reduction via Gamma-convergence in the context of elasto-plasticity.