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Nastran In-CAD Thermally Bonded Contact Anomaly/Discontinuity

Nastran In-CAD Thermally Bonded Contact Anomaly/Discontinuity

Nastran In-CAD Thermally Bonded Contact Anomaly/Discontinuity

I am performing a thermal analysis of a metal bar. The upper portion is insulated while the bottom portion is radiating to an ambient environment of 3000 F. The entire volume is subject to a temperature dependent generation load. The real bar is continuous, but was sliced in the model into separate bodies to allow the application of different loads and surface conditions to each segment. A bonded contact was applied between the bodies but does not appear to be having the desired affect. There is a clear discontinuity in the flux at the junction between the bodies. I have tried mesh refinement and redefining the surface contacts with no change. I even went so far as to make all the conditions on both sides of the contact identical and there were still temperatures indicated in the negative thousands of degrees.

Am I missing something with how to apply a surface bond that will simulate material continuity?

Any feedback appreciated. Thanks in advance.

RE: Nastran In-CAD Thermally Bonded Contact Anomaly/Discontinuity

I think that you are defining a contact which will merge the both bodies, making them move together. If I am rigth, these kind of contact is not what you need for thermal analysis.

What would I do?
1.- All preprocessors allow you to work with differents components, so it is easy to work with the entire bar, without breaking it, and apply different conditions for each component.
2.- If that is not possible, try to make a thermal contact.
3.- The last option is to use CONROD elements (see the QRG for more info), linking avery node with its pair on the other body.

I hope it helps.

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