# large deformation

## Large Deformation - Definition of total work energy density

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Like we have the elastic strain energy density for small deformations  defined as 0.5* σ :e  .

Is the equation PK2:E valid for the total work energy density for elastoplastic regimes ? If not, what would be a valid equation for total energy density ?

How can we decompose total work density into elastic work and plastic work densities for a large deformation case.

Where,

PK2 is the second piola kirchoff stress tensor

E is the Green-Lagrange strain tensor

Thanks,

Prithivi

## Elastica arm scale

Can configurational forces be exploited to design a new type of scale?

See the explanation and an example of use at http://www.ing.unitn.it/~bigoni/elasticscale.html

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## How to get the update the local material coordinate in large deformation for hyperelasitc rubber-like materials?

Hello,

I want to ask things about the updation of local material coordinate in large deformation.

Does there exist two ways for this?

1. Polar decomposition of Gradient Deformation Tensor F to get the rotation tensor.

2. Update each basis vector of local material coordinate system using modified Gradient Deformation Tensor F_bar = F*J^(-1/3).

What I cared about is the second method, is the second method available?

Wish someone could help me, : ). Thanks!!

## Harnessing snap-through instability in soft dielectrics to achieve giant voltage-triggered deformation

For a dielectric elastomer membrane we show giant voltage-triggered expansion of area by 1692%, far beyond the largest values reported in the literature.

## Cardboard rolls on the nanoscale

Everybody knows that cardboard paper can be a highly
anisotropic material. You can easily bend or roll it in one direction
and it is stiff in the other. If you take a close look you will find
that the paper is periodically buckled along one direction. We have now
exploited this phenomenon on the nanoscale to define the roll-up
direction of ultra-thin membranes on a substrate surface.

## Disparity in Simple Shear solution in ABAQUS

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Dear All,
We tried to simulate simple shear using ABAQUS and compared it with the analytical solution. To our surprise, even though the equivalent stress and strain matched perfectly, the component stress and strain had a large deviation between the semi analytical and ABAQUS methods. The zero components in the analytical model were calculated to be non-zero in the results of ABAQUS. This paradox could not be understood clearly as whether it is a case of software deficiency or conceptual error. A COMPLETE ANALYSIS OF THE PROBLEM IS ATTACHED AS A REPORT.