First attempt at material nonlinearity, problem with plastic region
First attempt at material nonlinearity, problem with plastic region
(OP)
Hi all,
I finally got my model of helical spring compression to run.
Initially to keep the model simple, I define only E = 29,000,000 psi and PR = 0.3. The result seems a little high especially at the toward the end with larger compression (see attached graph).
Then I attempted to define both the Elastic and Plastic regions.
Elastic:
E = 29,000,000 PR = 0.3
Plastic:
Yield Stress Plastic Strain
1 29,000 0
2 35,600 0.000235
3 42,600 0.000474
4 63,400 0.001377
5 69,600 0.0018
With the plastic region included, the result is too low (the final force is only 40% of test data).
What am I doing wrong? Many thanks,
I finally got my model of helical spring compression to run.
Initially to keep the model simple, I define only E = 29,000,000 psi and PR = 0.3. The result seems a little high especially at the toward the end with larger compression (see attached graph).
Then I attempted to define both the Elastic and Plastic regions.
Elastic:
E = 29,000,000 PR = 0.3
Plastic:
Yield Stress Plastic Strain
1 29,000 0
2 35,600 0.000235
3 42,600 0.000474
4 63,400 0.001377
5 69,600 0.0018
With the plastic region included, the result is too low (the final force is only 40% of test data).
What am I doing wrong? Many thanks,





RE: First attempt at material nonlinearity, problem with plastic region
Please leave your model here to be considered.
Good Luck,
Mohammad Shahbazi
http://www.omranafzar.com
shahbazi@omranafzar.com
----------------------------------
Please DO NOT respond to me directly but post all responses here in the newsgroup so that all can share the information.
RE: First attempt at material nonlinearity, problem with plastic region
RE: First attempt at material nonlinearity, problem with plastic region
Mohammad Shahbazi
http://www.omranafzar.com
shahbazi@omranafzar.com
----------------------------------
Please DO NOT respond to me directly but don't hesitate to post your response here so that all can share the information.
RE: First attempt at material nonlinearity, problem with plastic region
1) Where is the stress-strain data that you are basing the material model on? Is it from a tensile test..?
2) Are you using true stress and strain?
Regards
Martin Stokes CEng MIMechE
RE: First attempt at material nonlinearity, problem with plastic region
RE: First attempt at material nonlinearity, problem with plastic region
corus