Skip to main content

Nonlinear elasticity

Fluids, Elasticity, Geometry, and the Existence of Wrinkled Solutions

Submitted by Amit Acharya on

Amit Acharya, Gui-Qiang Chen, Siran Li, Marshall Slemrod, and Dehua Wang

(To appear in Archive for Rational Mechanics and Analysis)

We are concerned with underlying connections between fluids,
elasticity, isometric embedding of Riemannian manifolds, and the existence of
wrinkled solutions of the associated nonlinear partial di fferential equations. In
this paper, we develop such connections for the case of two spatial dimensions,
and demonstrate that the continuum mechanical equations can be mapped into
a corresponding geometric framework and the inherent direct application of
the theory of isometric embeddings and the Gauss-Codazzi equations through
examples for the Euler equations for fluids and the Euler-Lagrange equations
for elastic solids. These results show that the geometric theory provides an
avenue for addressing the admissibility criteria for nonlinear conservation laws
in continuum mechanics.

 

 

 

A Geometric Theory of Nonlinear Morphoelastic Shells

Submitted by arash_yavari on

We formulate a geometric theory of nonlinear morphoelastic shells that can model the time evolution of residual stresses induced by bulk growth. We consider a thin body and idealize it by a representative orientable surface. In this geometric theory, bulk growth is modeled using an evolving referential configuration for the shell (material manifold). We consider the evolution of both the first and second fundamental forms in the material manifold by considering them as dynamical variables in the variational problem.

The Geometry of Discombinations and its Applications to Semi-Inverse Problems in Anelasticity

Submitted by arash_yavari on

The geometric formulation of continuum mechanics provides a powerful approach to understand and solve problems in anelasticity where an elastic deformation is combined with a non-elastic component arising from defects, thermal stresses, growth effects, or other effects leading to residual stresses. The central idea is to assume that the material manifold, prescribing the reference configuration for a body, has an intrinsic, non-Euclidean, geometric structure. Residual stresses then naturally arise when this configuration is mapped into Euclidean space.

Nonlinear free and forced vibration analysis of a single-walled carbon nanotube using shell model

Submitted by Payam Soltani on

 By :Payam SOLTANI, J SABERIAN, R BAHRAMIAN, A FARSHIDIANFAR

In this Paper, the nonlinear free and force vibration of a single-walled carbon nanotube (SWCNT) with simply supported ends is 

investigated based on von Karman’s geometric nonlinearity. The SWCNT described as an individual shell and the Donnell’s 

equations of cylindrical shells are used to obtain the governing equations. The Galerkin's procedure is used to discretized partial 

Energy formulations of nonlinear elasticity including electric / magnetic couplings

Submitted by liuliping on

Equilibrium theories for a continuum body may be formulated by either of the
following the classic paradigms: (1) We begin with the stress postulation (Cauchy’s formulation) and write down the kinematics, conservation laws, and
constitutive relations. In this way, one can obtain a system of field equations
which, presumably, can be solved upon specifying boundary conditions and
determine the equilibrium state of the body. (2) A second way is to start from
the energy postulation (Green’s

PhD Position in Geometric Mechanics at Georgia Tech

Submitted by arash_yavari on

I am looking for a new Ph.D. student to work on discretization of nonlinear elasticity using geometric and topological ideas. Requirements for this position are a strong background in solid mechanics and some background in differential geometry and analysis. If interested please email me your CV.

Is it possible to model nonlinear elasticity in ANSYS with SOLID 18x elements?

Submitted by Freeman on
Choose a channel featured in the header of iMechanica

Dear all iMechanicians ,

Since several days I am trying to simulate a granular material very similar to sand. The uniaxial compression test performed to the material shows a nonlinear elasticity behavior during the unloading curve.

The goal is to fully reproduce the behavior of the material with a nonlinear elastic model when the material stress-state is inside the yield surface and the plastic behavior with a multilinear isotropic hardening law. The yield surface would be given by the Drucker-Prager-Cap criterion.

Joint Post-doctoral position: Masdar Institute (MI) and MIT

Submitted by skumaar on

Applications are invited for the position of
Post‐doctoral Research
Fellow as part of a joint research project between Masdar Institute of Science
& Technology and Massachusetts Institute of Technology (MIT). Details of the position are given in the attachement.

Linear Elastic material behaves as Neo-Hookean in ANSYS?

Submitted by Breslavsky on

I solve the static bending problem for thin plate under uniformly distributed load acting orthogonally to the plate. I

need the solution up to quite large values of deflection (100

thicknesses, which implies the strains about 100%), but I want to take

into account only geometric nonlinearity and not the material

nonlinearity. I use elements which support large strains (SHELL181,

SHELL281). The software is ANSYS Mechanical APDL 12 and 13. Also, I use "Large displacement static" option for

solution.