# ramdas chennamsetti's blog

## Theory of Representations for Tensor Functions—A Unified Invariant Approach to Constitutive Equations

Hi,

I am looking for the following paper.

Theory of representations for tensor functions - A unified invariant approach to constitutive equations - Q -S Zheng, Applied Mechanics Reviews, 47(11), 545-587, 1994.

If anyone has this paper, I request you to share.

Thanking you,

Best regards,

## iMechanica app in a smart phone

Hi all,

I am thinking that it is a good idea to have 'iMechanica' smart phone app (like facebook, twitter etc). We can post/check blogs using a smart phone.  I request moderators and imechanicians to comment on this.

Best regards,

## Strain energy density function of a Transversely Isotropic Material

Hi all,

I was going through Constitutive Modeling in Continuum Mechanics. I came across the Transversely Isotropic Materials (TIM). I have a couple of doubts, which are listed in the attached pdf file. I request the Continuum Mechanicians to clarify.

Best regards,

Normal
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false
false
false

EN-US
ZH-TW
TH

## ANSYS-LSDYNA Tutorials

Hi all,

I am looking for ANSYS-LSDYNA tutorials. If anybody has, I request him/her to kindly share or post the links.

Thanking you,

With best regards,

Hi all,

I have attached a single slide ppt file with this blog. In this slide, there is a hollow cylinder subjected to internal pressure and non-uniform axial load. All the translations at the bottom of the cylinder are fixed. As a whole the cylinder is subjected to a complex loading. The cylinder is modeled using SHELL elements in ANSYS. Now I know how to carry out non-linear buckling analysis in ANSYS.

## Stress based FE is not popular. Why?

Hi all,

I have a doubt as follows.

"Why stress based Finite Element Analysis / Method is not popular compared to displacement based FE?"

With regards,

- Ramdas

## Hermite interpolation functions

Hi all!!!

In Finite Element Method (FEM), Hermite interpolation functions are used for interpolation of dependent variable and its derivative.

In FEM books, Hermite interpolation functions are directly written in terms of Lagrange interpolation functions. No derivations are given. I searched in Numerical methods books also for derivation of Hermite interpolation functions. I couldn't find.

I am looking for the origin (basically the derivation) of Hermite interpolation functions. Kindly help me.

- Ramdas

## Spectral Element

Hi all,

I have just started learning (working) on spectral element method for modeling elastic wave propagation. I wrote a small code for bar spectral element. There is some problem in reconstruction of signal. If anybody is working in this area may write back. I will send my code. If anybody is having a sample code, I requet them to kindly share.

With regards,

- Ramdas (rd_mech@yahoo.co.in)

## Complmentary Strain Energy - Nonlinearity

Hi all!

I read that the "cmplementary starin energy of a structure is not equal to sum of the complementary strain energies of it's components, if there is non-linearity like geometric"

That means for e.g. if I consider a truss stucture subjected to loading so that it undergoes geometric non-linearity, then the sum of the complementary strain energies from members is not equal to complementary strain energy of the structure.

I request somebody to explain why is it so??

Thanks and regards,

- Ramdas

## Complementary strain energy - Non-linearity

Hi all!

I read that the "cmplementary starin energy of a structure is not equal to sum of the complementary strain energies of it's components, if there is non-linearity like geometric"

That means for e.g. if I consider a truss stucture subjected to loading so that it undergoes geometric non-linearity, then the sum of the complementary strain energies from members is not equal to complementary strain energy of the structure.

I request somebody to explain why is it so??

Thanks and regards,

- Ramdas

## Polar decomposition

Hi all,

I went through a topic on polar decomposition of deformation gradient. I understood the mathematics. I would like to know the physical significance and application of this. I request somebody to explain this.

Regards,

- Ramdas

## Cubic symmetry

Hi all!!!

Could anybody please give some examples of materials possessing cubic symmetry (these materials need three independent elastic material properties).

Thanking you,

- R. Chennamsetti

## Potential for Strain energy

Hi all,

When a conservative force does work, it is independent of the path, we define the potential and work done is given by  - (change in potential).

We define potentials for gravitational force, electrical force etc...

Assuming the body is linear elastic, internal forces, cause stresses in a body, are also conservative forces, whose work (strain energy) is independent of the path. Can we define potential for such internal forces? If so, we can calculate strain energy = -(change in potential).

You may kindly explain this.

## Body couples

Hi all,

We come across body loads such as gravitational, cenrifugal, magentic etc. Similary do we have body couples? If so, I request you to throw some light.

- Thanks & regards,

- Ramdas

## RMS Wave front

Hi all,

I just want to know how do we calculate the RMS wave front in frontal solver...

Thank you,

- Ramdas