Hello Biraj Dey ,
1. What are the 2 faces that you selected to define the location? and why?
I had split the constraining face in two parts (as shown in attached image), although that is not necessary.
2. how to create originating point location? and why?
3. What is significance of "apply from originating point"?
Originating point location is an arbitrary point via which the remote displacement constraints can be applied.
For a simplified example, I have considered the tube to be resting at one point, you can define it as per your understanding/ requirement of the problem statement.
For detailed information about the remote displacement and terminologies associated with it, please refer the AIM documentation.
3. Can you explain step by step procedure to define a pin support at extreme one end. of the same circular c.s. (i.e., without any overhang after that, H=0)
To constrain the model on the extreme end of the tube,based on my understanding of the problem, I would follow same procedure as mentioned earlier, with the outer face (refer the attached image) as the constrained face, lower most point as originating point and co ordinate system at same location as reference frame.