I need to model a simple body in Abaqus. The material should have two types of properties- it should behave like a viscoelastic material under a certain given temperature, and like a viscous material upon further heating.
I shall be defining the material behaviors directly from the key-options already provided in Abaqus.
How should I proceed?
I am using Abaqus Explicit.
I am afraid that it may not be possible to model such material with the options directly available with ABAQUS. You may have to write a UMAT or VUMAT.
Thanks a lot for the info Mr. Faye. I appreciate your help.
I read somewhere that you only need a subroutine when you can’t define the material using just the predefined options in Abaqus.
As I'll be only using the predefined options, is writing a VUMAT necessary (I am using Abaqus/Explicit). What all information do I need to have to write one (I already know how to use Fortran77).
From your question it seems that your material model depends upon the temperature also. I don't think you can just switch from one material to other depending upon temperature, using predefined options. However that may be possible using VUMAT. Btw are you doing coupled temperature-displacement analysis??
Yes Mr. Faye, your assumption is correct. My analysis does depend on temperature; but it's not a coupled temperature-displacement analysis, as there is no heat being generated due to mechanical stresses. It is a basic Thermal Displacement analysis, in which I aim to see in which way does the body melt.
Again, is it possible to define a VUMAT with (for example) a *TRS and Arhenius relation? What all experimental/theoretical data might I need for the same?
Sorry I will not be able to tell you how exactly you will be able to do that. However for writing a VUMAT you should have complete formulation for viscoelastic constitutive model with a relation to update stress at each time step.
That's completely ok. I understand, and I appreciate your help Mr. Faye!
Hope you have a great day.
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