I am trying to place two lego blocks on top of each other, and finding the force needed to fit them into each other. I conducted a nonlinear study, using a prescribed displacement that puts the two blocks exactly on top of each other, I got a force of 8N, which I thought was too small.

After that, there is a no penetration contact set between the 2 blocks, so I added the prescribed displacement so the blocks are squeezed more together, and logically, got a higher force.

Is what I am doing logical to estimate the actual force needed to squeeze the two parts together?