Free expansion in Abaqus

[Ashu28]

Hi,
I was trying to simulate free expansion (to get started on a complex problem, I first wanted to understand this) in ABAQUS. I made a simple 2 D long rectangle. Defined E (modulus), poisson ratio, Expansion coefficient (with 0 in Ref Temp), and Thermal Conductivity. Used Coupled Temp-Displacement Analysis (regular general analysis wont let me specify Temp BC on STEP 1). Used CPE4T element. Left face constrained at INITIAL and at STEP 1, the whole part gets Temperature BC of 100 (raise the temp of part by 100).

I was expecting that in the result I should see a strain of alpha*delta_theta and 0 stress. Instead I see a stress of E*alpha*delta_theta. This doesnt seem right.

Does anyone know what am I doing wrong?

Also, why do I have to specify conductivity? I dont use it in analysis?? Abaqus wont run, some error about DOF 11 not active otherwise

Regards,

 

[TGS4]

Don't perform a Coupled Temp-Displacement analysis. You are solving for both temperature and displacement. (And you need conductivity to solve for temperature, so...)

Do what you were first trying, but instead of applying temperature as a load, apply it as a predefined field.

 

[Ashu28]

Thank you for the reply.
So what would I chose in Step? Static General? How do I apply a predefined field? I will search this option tomorrow in ABAQUS when I go back to work....I dont remember seeing it anywhere in CAE though...