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API : export Nodal stress to .csv in order to use it with fatlab

Hi together,

 

I am looking for a fatigue analysis software and found this: http://fatiguetoolbox.org/

It makes a good impression despite the fact that there's no interface to FEMAP.

 

I read some posts about getting out nodal stresses herein -  but befor I start trying to develop an API:

 

- did anybody tried out FATLAB with FEMAP already?

- does anybody already tried to program an API in order to get out nodal stresses like below:

 

Stress export: node no., SX, SY, SZ, SXY, SYZ, SXZ
1,3.7834,0.26638,0,-3.00E-02,0,0

 

thanks & regards,

 

der Rechenschieber

2 REPLIES 2

Re: API : export Nodal stress to .csv in order to use it with fatlab

Siemens Phenom Siemens Phenom
Siemens Phenom

NASTRAN does not produce nodal stress tensor data. Output data from NASTRAN is elemental centroidal stress tensors, and then optionally, for each element, the stress tensor at its nodes. Nodes then have stress tensors reported for all elements connected to that node. For 3-D solids, with defaults options, they’re all aligned in a global coordinate system. We could write an API that dumped out the average SX, SY, SZ…….. for each node of a solid mesh. It gets more difficult with shell meshes where the corner stress tensor is in the element’s coordinate system, therefore the X direction at each nodes varies for the elements connected to it, it’s more work to figure out an appropriate tensor.

 

Are you working with solids, or shells?

 

Mark.

Re: API : export Nodal stress to .csv in order to use it with fatlab

Hi Mark & thanks,

 

yes, this I got already as well: NASTRAN does not give out nodal stress just like this & that it would be necessary to write an API to do so. Since I am not that familiar with API & just wanted to give fatlab a try it seems to me quite work to write  an interface by myself. I think I will stick to WINLIFE for my fatigue needs in future.

 

thanks,

der Rechenschieber