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FEA simulation error

4 REPLIES 4
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Message 1 of 5
H_J_S
267 Views, 4 Replies

FEA simulation error

I have a FEA analysis in inventor proffesional containing both shells and solids. After running the analysis some times i suddenly get the error
"The coordinate system is referred but not defined" Then the analysis ends. After this it seem impossible to restore the model to a level where it can be calculated. The only option is to delete the simulation and start all over which takes several hours to set up. What do I do wrong? Does anyone know what to do when sgetting this error. I tried the FEA FAQ. No help there. I ahve tried makin a brand new file on a nother computer. the result is the same. after x amount of simulations I get the error.

4 REPLIES 4
Message 2 of 5
raviburla
in reply to: H_J_S

Hi,

 

Would you be able post your model or a simplified one which reproduces this behavior?

 

Thanks,

Ravi Burla



Ravi Burla
Sr. Principal Research Engineer
Message 3 of 5
H_J_S
in reply to: raviburla

Unfortunately not due to compagny policy. I would not know how to recreate the error.

Message 4 of 5
raviburla
in reply to: H_J_S

 

Can you let us know what type of loads/constraints/contact conditions, solid mesh or shell mesh or mixed mesh for the modeling? 

 

Thanks,

Ravi Burla



Ravi Burla
Sr. Principal Research Engineer
Message 5 of 5
H_J_S
in reply to: raviburla

Pressure loads on tubes:

On shell tubes - Only internal pressure is intended
On solid tubes - internal pressure on inside and some pressure on the outside as well in local regions inbetween shells

Mixed mesh - Auto refine to find 10% convergens on selected solids during analysis

No special demands for shells

 

Mesher set to:
min/avarege 0,5

Curved mesh

Grading 1,6

 

(Mesher works fine by the way)

 

I work with combination of bonds / sliding no separation / separation

I work with a local cut of of a larger steam boiler so I use the vector compoents Rx, Rz, Ry, Uz, Ux, Uy to define the degrees of freedom.

At first i thourght the error was here (error by me in set-up) - but I have similar models that worked fine in Inventor 2014 and now they do not in 2015.

 

Is there any trouble using Rx, Rz, Ry, Uz, Ux, Uy on solids in combined shell / solid enviroment?
I mean - In a pure solid only Uz, Ux, Uy is available for vector options

 

Is there any trouble using internal pressureon shells - I do not have the impression - but still

 

NB
When doing the 3-D I drew one solid body for the shells (patterns) and one solid body for the solid.

in the stress enviroment the shell feature results in division into app. 350 separate shell bodies tube/fin tube/fin etc.

 

The mesher is quite quick - and also the calculations (when it works) are performed in an acceptable pace.
So we think the setup is pretty good and we have refined the method over app. 100 or more anayisis of similar set up.

BR

Hans

 

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