Learning Forum

[Andreyteston]

Hello, members.

I would like to use this relationship for the concrete on the confinement effect.

I have already tried these models: 

Multilinear Kinematic Hardening Constants (TB,KINH) and Multilinear Isotropic Hardening Constants (TB,MISO), however, in these models is not a possible constitutive relationship stress-strain with negative slopes.

Nonlinear Isotropic Hardening Constants (TB,NLISO), however, in the models is not possible to add the constitutive relationship stress-strain.

Actually, I have been tried Multilinear Elastic Constants (TB,MELAS), on the other hand, reading about this model, I have found in ANSYS help: "This behavior, unlike the other options, is conservative (path-independent). The plastic strain for this option should be interpretedas a "pseudo plastic strain" since it returns to zero when the material is unloaded".

1. Does this mean that material behavior will be linear even that my analysis will be non-linear?

2. Is it possible to put my constitutive relationship stress-strain using Experimental Data (TB,EXPE)?

I would like to obtain help.

Regards.

[Wenlong]

Hi Ândrey,

Sorry about the late reply. 

I don't think hardening laws should be used for your case because as you mentioned, we cannot define negative slopes in these models. To define your stress-strain behavior you will need other material models. 

Microplane material model can capture damage (which is responsible for softening behavior) and has been applied for concrete modeling. It could be a candidate for your simulation. You can find more information here: https://ansyshelp.ansys.com/account/secured?returnurl=/Views/Secured/corp/v194/ans_mat/microplane.html?q=microplane

Here is an example of using Microplane material in reinforced concrete joint: https://ansyshelp.ansys.com/account/secured?returnurl=/Views/Secured/corp/v194/ans_tec/tecreinfconcresults.html

There are many material constants you will need to calibrate from your test data. Good luck!

Regards,

Wenlong

 

[Andreyteston]

Hi, Wenlong!

No problems with the time, I really would like to thank you for your contribution. 

Knowing that hardening laws represent positive inclines in the stress-strain behavior and evidently not support negative slopes, based on your information, I won't use these material models.

So, I will use the Microplane material model. Based on your information, I will mark this topic with the solution. 

Thank you again for the help and for your wish for good luck.

Regards.

Ândrey