In my design the threaded portion is actually connected to the force testing machine and the hole portion (pin portion) is bolted to padeyes which has to be tested for force test. So my doubt is where should i give the conditions, where should i apply the load (at bolted area? or pin area? ) . where should i fix the geometry? how can i optimize the design will my design able to withstand the force?
Hi @antonysanju37, thanks for posting on the forum and welcome to the SimScale Community 
It’s a bit hard to uderstand the exact problem you’re trying to simulate only by a written description. Could you provide some extra details and maybe a schematic of what you’re going for?
I’ll give you a general guideline on boundary conditions for FEA though:
- Clean your CAD: If necessary, clean your CAD so that it only contains the necessary details for simulation. (Documentation)
- Constrain your model: In reality, if stresses are being developed in a static scenario, your assembly needs to be constrained, i.e., there should be a reaction to the applied loads. The most common constraint would be a Fixed support.
- Apply loads: where are the loads applied in reality? You should apply the loads in the corresponding place in your simulation. You can do this by splitting a surface for instance so you can apply the load only on a portion of it.
Steps 2 and 3 are what we call boundary conditions.
Cheers
Igor