Learning Forum

[Ibtehal]

Hi every one

I used nonlinear analysis by rate independent- general isotropic hardening- vonmisses-multinear 

When enter stress strain curve in ( stress vs total strain) for sand Ansys apdl it accepts strain only when multiply by 100 except first value it takes it = stress/E

can anyone help I will be thankful, am I right or what ?

[peteroznewman]

Please reply with the complete table you are trying to enter (with units) and the value of E.

[Ibtehal]

[peteroznewman]

The two columns are Plastic Stain and True Stress.

The first row should have 0.0 for plastic strain and the Yield Stress.

Your tables don't have a 0.0 for plastic strain in the first row.

For a quick and approximate adjustment, subtract 0.001191429 from every value of strain in the top table.

The bottom table is just plane wrong if E is 30 MPa as you claim. Just delete that.

For an accurate adjustment, read this post on Multilinear Kinematic Hardening.

If you plot your data, you might consider setting the yield stress to 0.145 MPa and starting the table at that row.

You could even dispense with Multilinear and go with Bilinear Hardening, where the Tangent Modulus is 18.4 MPa