General Mechanical

General Mechanical

Material model to input the stress-strain relationship for concrete with a negative slope

    • 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.


    • Wenlong
      Ansys Employee

      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:

      Here is an example of using Microplane material in reinforced concrete joint:

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




    • 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.





Viewing 2 reply threads
  • You must be logged in to reply to this topic.