ABAQUS General Beam Section - SENER

[mcclain]

SENER - Elastic strain energy density, per unit volume.

The SENER results provided for a standard cross-section are very different from those for a general beam section using properties of the same cross-section.

This is the answer that I received from ABAQUS.

"The output in both cases is per unit volume.

In your model with a pipe section there are 8 section points around the perimeter of the pipe whereas for the general section there is only 1. The sum of the densities for the pipe section divided by 8 gives a number close to the energy density output for the general section. The remaining difference can be attributed to differences in the cross-section properties being used (this can be verified by printing out model information and looking at the inertia properties calculated by ABAQUS)."

I don't understand the reply and I can't figure out how to even ask a follow-up.

The problem is a test case which is as follows:
Cantilever beam
Length = 10in
Cross-section = pipe with outer radius = 0.5in
inner radius = 0.3"

Loading is a 0.2" deflection at free end with this end free to rotate.

Material constants are E = 26E6 psi
Poison's Ratio = 0.34

SENER using B32 element = 74in.lbs/cu.in

SENER using GENERAL SECTION = 19.65 (something’s, not even sure what the units are).

Any thoughts would be appreciated.

 

[xerf]

Besides SENER, the other results (e.g. displacements) from the two cases are the same ?

 

[mcclain]

Xerf,
The analysis is deflection driven at the tip.
The other displacements are within one tenth of one percent of each other.

The general section cantilever stress and moments match the classical elastic solution within one percent.

The standard pipe section forces and moments are slightly less than the clavicle solution by about six percent.

Thanks
Mark

 

[xerf]

SENER is output at integration points and should vary in space and you gave a constant value for each case.

 

[mcclain]

Xerf,
The values given are the maximums. For the pipe section (74in.lbs/cu.in), its the maximum out of four integration points.
For the general section its the only value given. If I assign section points to the general section (*SECTION POINTS) I get nothing for SENER.

Thanks