Real Time Node Output

Altair Forum User

Hallo everybody,

I' have a questaion about node outputs. Is it possible to give an output like reaction forces for a specific node every timestep in real time?

I' would like to log the reaction force on the node in real time to stop the simulation at a specific force.

It would be the best if the information about the node are wirtten to an ASCII File to generate a Force-time curve for the specific node.

 

Hope anybody of you have an idea!

 

F.M.

Altair Forum User

Hi F.M

 

Please refer to the post:  http://forum.altairhyperworks.com/index.php?/topic/13966-plot-force-x-displacement-impact-analysis/

Altair Forum User

Hi Prakash,

thanks for your quick answer. But the post is not actually about the problem I have.

In the post the XY-Plot is created after the analysis. I want to create the Plot (or a file with the data) parallel to the simulation.

So for example I have an Force-Displacement output and want to stop the simulation if the force reaches 1000N for example.

It's a kind of real time tracking I think.

 

F.M.

Altair Forum User

Hi Fabian,

 

I dont think there is a way to sync for real time output. I have to check this with developers.

 

but, you load the T01 file in HyperGraph during the run and can view the results. T01 keeps on updated. So load T01 file and click apply when ever T01 is updated when the job is in progress.

Altair Forum User

Hi Prakash,

 

thanks for your answer. The method you describe in your post i'm using actually. But in the future I would like to do this automatically.

I also try to generate an output with *.sty ASCII Files. But the Problem is that the output is for all nodes and so the file is very big. Also it is very time consuming to search for the interesting line in this big file.

 

Maybe it is possible to control HyperGraph by a tcl script to do the steps you describe above automatically - i do not know?

 

F.M.

Altair Forum User

Hi,

 

I will check with experts about this and also I will create an RFE to add this feature in future releases. /emoticons/default_smile.png' alt=':)' srcset='/emoticons/smile@2x.png 2x' width='20' height='20'>

Altair Forum User

Hi,

thank you for your effort. I hope you will find a solution.

 

F.M.

Altair Forum User

Hi,

is it mybe possible to read the TimeHistory File with an other external Programm?

The main Problem is that the Inforamtion I need are stored in this file but i can not read it.

 

F.M.

Altair Forum User

Hey Prakash,

 

have you already a solution?

 

F.M.

Altair Forum User

Hi FM,

 

what external program are you referring to?

 

is it a text reader or an application?

Altair Forum User

Hi Prakash,

 

at the moment I'm using a C++ program. But this is not necessary if there is an better solution.

All I need is an program, wich can read the Time History file for example every 2 seconds and track the Force of a specific node. In the best case it is a scripting or program language.

 

For example the C++ program I'm using actually using is reading the *sty ASCII files which are an output of the simulation. The program search in this file for the specific node ID and writes out Displacement and Reaction Force. If the program notice that the force does not growth for 20 times, the simulation is stopped.

The problem is that the ASCII files include the information for all nodes. SO it is very time consuming to search the specific node ID. This is the reason why I would like to have such an output only for the nodes of interest (mybe 3-5 nodes).

The Time History file do exactly this thing but the problem here is, that I can not read this file format with the C++ program, or I'm wrong?

So I see only two solutions:

1.) Do the live tracking with an HyperWorks program like HyperGraph

2.) Find an external software, which can read the Time History format.

 

I hope now you understand the kind of problem I have.

 

F.M.

Altair Forum User

Hi Prakash,

 

because of your response I suppose there is no easy solution for this kind of problem?

 

 

F.M.

Altair Forum User

Hi Fabian,

 

I have created an RFE for this.

Altair Forum User

Hi Fabian, 

 

can you try this?

 

You may use /STOP/LSENSOR option in engine that stops the job when a given sensor becomes active. The sensor /SENSOR shall be determined in starter. Activation can be based on force, nodal displacement, aceleration etc. 

Altair Forum User

Hi Prakash,

 

thanks for your answer! I have already solved the problem I had.

I wirte out the TimeHistory File in ASCII Format so that it is readable for other programs. When the solver is running, a second program (Python Code) read every step of the TimeHistory File and check the forces. This works very fine for me and the advantage over the 'sensor-method' is, that I can plot a stress-strain curve in real time parallel to the simulation. Also I can give other restrictions to stop the simulation for example a maximum internal energy or something else (every variable defined in the TimeHistory File).

Many thanks for your effort!

 

F.M.

Altair Forum User

Thanks for the update Fabian, /emoticons/default_smile.png' alt=':)' srcset='/emoticons/smile@2x.png 2x' width='20' height='20'>