Non-linear solution

[Drej]

Hi all

I've developed a model in ANSYS 7.0. It's basically a series of trusses forming a cage-like structures, modelled using beam4 elements. I apply nodal forces to the structure and get approx 6mm max deflection. The analysis appears to run fine, however when I solve the analysis, ANSYS states "non-linear solution". I cannot understand why, as I have only beam4 elements in the model (although i do have link10 elements, but these are deleted before the model is solved). No material non-linearity is included either.

Any thoughts?

Thanks in advance.

 

[juzz]

Hello, Drej!

If you used link10 elements you delete the elements but you delete the element type too ?

Best regards,

Juzz

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Justin Onisoru
Researcher
Romanian Academy,
Institute of Solid Mechanics
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[Drej]

Hi Jus,

No - I don't think so, only the elements generated are deleted I believe. Still, I think Link10 elements are "linear" elements anyway are they not, and therefore would not generate a non-linear solution?

Cheers,
-- drej --

 

[juzz]

Hello, Drej!

Please take a look at Chapter 14.10 from Ansys Theory Manual.
You will see that the solution is non-linear disregarding the non-linear or linear material you use. In fact the stiffeness matrix is not function of deformation but is function of the kind of deformation you have (it means compression-only or tension-only mode depending on your keyopt(3) setting).

Best Regards,

Juzz

----------------------------------------------
Justin Onisoru
Researcher
Romanian Academy,
Institute of Solid Mechanics
----------------------------------------------