Learning Forum

[Luca Schnell]

Hello everyone, i am working on a project where i have to simulate the measured residual stresses and i would like to get some feedback to make sure that i am doing this correctly according to your opinion. I proceed as follows:

1. I am exporting the point cloud from FEM
2. Then i assign each point with σ XX, σ YY and τ XY
3. I reimport the extended point cloud to Ansys
4. I define it as initial stress
5. Lastly i use a Remote Displacement on my object so it is free to deform due to residual stresses.

Thank you in advance

Luca

 

[peteroznewman]

How are the residual stresses measured?

Here is how I simulate residual stress:

1. Create a material that uses one of the Plasticity material models such as Bilinear Kinematic Hardening.
2. Create support boundary conditions.
3. Apply sufficient load to the intital geometry to cause the material to exceed the yield strength.
4. Remove the load.
5. Plot the residual stress.
6. Plot the residual deformation.

[Amin Lotfiani]

Dear Peter,

I am trying to find the residual stress in a bent sheet metal. Could you also explain how I can calculate the residual stress or plot it as you mentioned above in step 4?

Thank you in andvance!

Kind regards,

Amin

 

[peteroznewman]

Dear Amin,

Use a 2 step analysis and make sure you have turned on Large Deflection.

In the Tabular data for the Force, step 1 will have a value for the applied force such as 820.0 units and step 2 will have a value of 0.0

Insert a Von Mises Equivalent Stress plot.  By default, the stress will show the results at the end of step 2. Any component of stress plotted at the end of step 2 is residual stress.

You can insert another result such as Plastic Strain to show that yielding has occured at the end of step 1.

-Peter

[Amin Lotfiani]

thanks a lot for the instruction!

I wasn't sure that that the end stress is in fact the residual stress. 

Kind regards,

 

Amin