Learning Forum

[shravanumesh]

Hi all!

I am covering a steady-state thermal analysis simulation of a gear tool. The first image is the figure of the model. The tool is in contact with the workpiece from the beginning for 5 seconds and then is moved away.

The second image is the result of my simulation. After adjusting the contact distance, this is the closest I could get to my intended temperature curve. I have marked two regions: Area 1 (red box) and Area 2 (green).

1. There is a fluctuation in tool temperature in Area 1 even though there is no movement.
2. The temperature is slightly decreasing in Area 2 whereas it should be increasing.

What checks can I do in LS-Dyna to ensure I get the correct trend?

Thank you!

[tslavik]

Hello What is the setting of SOLN in *CONTROL_SOLUTION?
ref: 2021072310000047

[shravanumesh]

SOLN 1. Thermal analysis only.
I have solved the issue. The problem was with incorrect contact (for area 2 - green region in the image)
For anyone referring this thread for solution:
Since it is thermal analysis only, I used birth time and death time given in the contact option to avoid moving my model. Yet the oscillations (Area 1 - red region in the image) existed. Using PTYPE = 0 and SOLVER = 3 in THERMAL_SOLVER and Fully implicit (TIP = 1) option in THERMAL_TIMESTEP help smoothen the curve