Learning Forum

[Joe Kirkup]

Hello! I am new to ansys and i'm looking to implement a customised step contact between two bodies. The contact should alternate between being thermally conductive and having no thermal conductivity, but maintaining the mechanical stiffness aspect throughout. I then want to implement this into a wider APDL script based on some step timings I calculate. 

My current approach in Workbench has been to set the 'Normal Stiffness Factor' to 1 for all steps and just alternate between dead/alive and just hope that the thermal conductivity alters. This has brought me no joy, as when I hit the first dead step contact the mechanical contact is void and the bodies pass through eachother. 

I assume there is an APDL script that will allow me to set thermal conductivity to 0 (or a very low value) and maintain the mechancial aspect in a loop for a number of steps; however I am a real novice when it comes to scripting and would appreciate any help you can provide. 

Many thanks,

Joe

[mjmiddle]

Is this a coupled thermal-Mechanical analysis or one way linkage of thermal transferred to Mechanical?

To do it entirely in a script means the script would have to take over the entire solution process. Instead you can insert a command snippet for each load step, and specify the load step for which those commands apply:

Or to do it with no commands, insert two contacts. One is the thermal contact. The other is Mechanical contact. For the thermal contact put a reasonable contact thermal conductance coefficient and a very low normal stiffness factor. In the second contact, you can put a very low thermal conductance coefficient and leave normal stiffness factor as program controlled or some reasonable value, like 0.01

For the Contact Step Control, you can see there is a normal stiffness factor where you can set a different one for each load step instead of dead/alive. But you can't vary the thermal conductance coefficient that same way.