Abaqus TEMP Output vs Input

[lmorand]

Hey all, a quick question about AM simulation in Abaqus. Hopefully this is something simple I'm just not quite grasping.
As you know, in thermo-mechanical simulation, it is a 2-step, sequential process. The NT output of the heat transfer simulation becomes the input to the mechanical.
I pulled the TEMP results from the .odb of both the heat transfer and the mech simulation, expecting the temperature evolutions to be the same. However, the mechanical (ST) results are generally ~500 degrees cooler at each point.

As far as setup, this is for a five layer part, not including the build plate. Since the mechanical simulation is a mechanical one, I'm unsure how it could be changing the temperature history. This occurs no matter the model's layer total.

I feel I should be getting the exact same temperature curve for both. I appreciate any clarification you can provide!

 

[FEA way]

Is NT12 the same in both simulations ? Is initial temperature defined for mechanical analysis ?

 

[lmorand]

I only have NT11 as an output (C3D8R).

My mechanical analysis only has an encastre BC on the build plate portion of the model (not my part) and uses a predefined field to assign the HT values.

I really don't understand where the heat could be going. It's a mechanical analysis, and the build plate definition is the same as in the HT analysis so it shouldn't be experiencing any extra conduction.

 

[FEA way]

Yeah, I was thinking about NT11 but I wrote NT12 by a mistake. Is NT11 also different in both analyses ?

It’s a simulation of an additive manufacturing process, right ?

 

[lmorand]

Yes, this is simulation of L-PBF using the AM plugin.

I just compared values of NT11 instead of TEMP.
This time, the values are the same! Time to dig in to the difference between TEMP and NT11.

Thanks for the help.

 

[FEA way]

The difference is that TEMP is a temperature at integration points of elements while NT11 is a nodal temperature.