Learning Forum

[murali macharla]

Hello Everyone,

I did a bending test and exported these stresses in a text file. Now, I am trying to map these stresses to another static structural where I want to apply a thermal load. In the new static -structural the CAD is made as bent and stress results are passed-in as pre-stress through External data module. I can able to map the stresses but the stress values are different from the exported stress values. Is this due to the CAD is different? is there anyway to map the stresses even if the cad is made as bent ? How, i can map the stresses and give them as a pre-stress without changing the stress values?. Could you please tell me if i am doing something wrong? or suggest me if there is any other way for pre-stressing

Note:- 1.) The no of elements are same in the both models and the elements are also linear(meaning nodes are same).

           2.) I can able to map the stresses from the bending test if the CAD is normal(see first 2 images) but I can't map if the CAD is made as bent.(see 3 and 4 images)

           3.) Please notice the stress difference in the attached images

 

 

Best Regards,

Murali

[Govindan Nagappan]

In the first static analysis where you compute the stresses, you can insert a command under "Static Structural" similar to
inistate,write,1,,,,,s

This will create a file named file.ist in the analysis system directory. From the project page, you can use View-> Files to see the file in the list and find its location. This file has the stress state from static analysis

Then in the next analysis you can insert a command under analysis branch similar to
inistate,read,file,ist,'C:\...\dp0\SYS-2\MECH'

Specify the location of the file.ist in this command. This should apply the stress state as initial condition

See if this helps

[murali macharla]

 

Hello,

I am doing it in the way you said by orienting it to the material co-ordinate system. While using the ” read ” command, i am geting an error continously saying that it cannot open the file. I have attached both the command snippet and error message screenshot.

 

[murali macharla]

Hello, I have solved the above error. Now, I applied the pre-stress. First, i want to know, whether it has imported the stress values correctly. So, i haven't applied any boundary conditions that might cause any deformation or any stresses.Then, I ran the simulation. Now, I can able to observe the deformation due to pre-stress. But, the deformation/deflection of the body due to pre-stress is opposite to that of the actual deformation. What is the reason behind this? 

[Lisa Kröger]

Hello Murali,

I get the same error as you mentioned before (cannot open file ...). Could you maybe explain how you solved this?