Nodal stresses from the element stress 1

[Mohanlal0488]

Hi Guys

I have been developing a FEM toolbox on Octave.

With regards to CST elements, the element stresses can be calculated using DBq.
The stresses attained can be takes as the stress at the centroid of the element.
How can one calculate the nodal stresses from the element stress?

 

[FEA way]

Stresses are extrapolated to nodes using shape functions. This is described in various books about FEM, such as "Concepts and Applications of Finite Element Analysis" by R.D. Cook. Also check the 28 chapter ("Stress Recovery") of "Introduction to Finite Element Methods" by C.A. Felippa (it should still be available as open-source book in the internet).

 

[btrueblood]

What FEA way said, but I'd call it interpolation rather than extrapolation...but that's just weaselly semantics.

 

[IceBreakerSours]

Just for fun, why would you call it interpolation? As I recall having understood post-processing in FE codes, it is extrapolation.

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