Reply To: Mechanical Clearence in Thermal-Structural analisys

[peteroznewman]

Is the thermal load a uniform temperature on both parts?  If so, then you don't need a thermal analysis, you can apply that load directly in Static Structural. It is called a Thermal Condition.

If the thermal load is uniform, I recommend you take advantage of symmetry. In CAD, put a plane half way along the length of the bar. Slice the parts in half and discard one half.  Put a plane parallel to the YZ plane through the center of the bar. Cut the parts using that plane and discard one half. Finally, rotate that YZ plane about the bar axis by 60 degrees. Slice the parts using that plane and discard the parts that have the 120 degree angle and keep the 60 degree parts. Now you can use 3 planes of symmetry to support the rod and hex part. You can keep the 0.1 mm gap between the parts. In Mechanical, use a Frictional or Frictionless contact between the two faces with the 0.1 mm gap. Under the Connections folder, insert a Contact Tool. Evaluate the Initial Contact Status and make sure the Contact Status is Near Open. If the rod has a larger CTE than the hex part, it will expand faster and at some temperature, the gap will close and the two parts will induce stress on each other.