Learning Forum

[MrJ16]

I am trying to model an elastic-plastic material using bilinear isotropic hardening to model the plasticity region. When I try to specify the yield strength and tangent modulus in tabular form, ANSYS just isn't accepting the final bit of temperature data.

I had tried the same with Isotropic kinematic hardening and had no luck. I am carrying out a thermo-mechanical analysis of a moving heat source on a metal coating so the temperature-dependent yield strength and tangent modulus are important.

Attached below are the values along with the error.

[Sean Harvey]

So, Ansys only support 6 temperatures per the documentation for Bilinear Isotropic Hardening. 3.2. Defining the Bilinear Isotropic Hardening Model (ansys.com), now I have to check if we can get engineering data to provide the TB,PLASTIC,,,,BISO which does not have such a low limit on number of temperatures. I will check what the limit is.
One workaround is to use the multilinear isotropic hardening. Then you just have to define two datapoints to represent your curve instead of specifying a tangent value directly. This is a bit more work, but Ansys write in the TB,PLASTIC,,,,MISO format which has a much higher limit on the number of temperatures.
I will circle back with some more data, but to get you moving forward, this suggestion should help. Thank you!
Regards Sean

[Sean Harvey]

.
So I have confirmed and there is no limit if you use multiliinear kinematic hardening as it uses the TB,PLASTIC,,,,MISO format. At 2021r2, engineering data does not yet support writing TB,PLASTIC,,,,BISO format, but it should at an upcoming release so that limit will be removed. If you still wish to use bilinear, you can create a command object under the part(s) with the tb, tbtemp, tbpt commands to define all your bilinear curves. Please let us know if you have further questions.
Regards Sean