Heat transfer between parts

[Anonymous]

Hello! I have been trying to use Inventor Nastran since last Friday and can't obtain the type of results I am looking for.

Let me explain myself: 

Reason for Nastran study: I have an aluminum mold made out of 3 pieces joined together with screws. A piece of carpet and rubber (both located under the mold during the pressing operation) comes out warped in production. Therefor we want to look at what is happening when heat is applied to the mold. Hopefully identify an area with high concentration of heat and correct the design.

Issue #1: I am applying heat on the top mold piece and while I am getting *some* results for the top piece, it seems like it is not transferring the heat to the other 2 mold pieces. I have no idea how to attach these pieces together in a way that Nastran understands that they are connected together and calculate the heat transfer properly.

Issue #2: I would like to see how heat transfers into the mold over a given period of time. Can anyone help me understand how that is achieved?

Best regards.

[John_Holtz · Accepted solution]

Hi @Anonymous . Welcome to Inventor Nastran.

Issue 1 sound like you have not defined contact between the parts so that the analysis knows that heat can transfer from one part to the next. Contact can be setup like in this tutorial Tutorial A1: Apply the Constraints, Loads, and Surface Contacts or in this self-paced training exercise Section 9: Contact Modeling.  The main difference between the tutorials and your model is that you want the parts to be bonded so that the heat will flow.

For issue 2, you should be performing a Nonlinear Transient Heat Transfer analysis so that you get results over time. After the analysis completes, the "subcase dropdown" will let you scroll through the results from different time steps. (Kind of like this image showing the different results or steps available from this fatigue analysis.)

subcase ribbon.png

Let us know what happens next. 

[Anonymous]

Perfect! Thank you so much! While it took a bit more fiddling, I eventually got everything to work by following your advice and ended up with credible results. Thanks again!