# ramdas chennamsetti's blog

## Odd order governing equation - FE formulation

Hi!!

We generally encounter governing equations of even order. In FE formulation we get a symmetric coefficient matrix 'A' (AX = B). I have a few doubts as follwing.

[a] Any odd order governig equations ? If so, you may please write.

[b] Say, it has a functional also, then, what's the order of that differentiation?

## Body loads in wave propagation..

Hi all,

 In solids, the wave propagation equation is obtained from stress equilibrium equations. We make use of constitutive and strain-displacement relations to convert these equations in terms of displacements

 In the above equations we assume that there are no body loads.

 The form of solution we assume for displacements is harmonic

 Plug these three displacements, u1, u2 and u3 in the equilibrium equations stated in .

 We end up with an Eigenvalue problem. This is nice.

## Thin plate theory...

Hi all!

I have a small doubt in the assumptions made in thin plate theory.

We make some of the following assumptions in thin plate theory (Kirchoff's classical plate theory) (KCPT).

 The normal stress (out of plane=> sigma(z)) is zero. and

 The vertical deflection 'w' is not a function of 'z' => dw/dz = 0

Now there are three stress components sigma(x), sigma(y) and sigma(xy). The other three stress components sigma(z), sigma(xz) and sigma(yz). This is like a plane stress.

## Spectral Finite Elements

Hi all!

I just strated using Spectral FE technique for wave propagation applications. I am looking for some example code (for bar/beam or any geometry). If anybody has, I request them to kindly send me.

- R, Chennamsetti

## Mesh free methods - literature

Hi all!!

Where can I get literature on Mesh free methods (basics)?

I am suggested Dr. Liu's book.

Please suggest me some more good literature (some web sites, text books etc), assuming that I am zero in mesh free methods.

## Pages 