Merging Mesh Question

So I recently created a mesh of a very complex shape. The shape itself is symmetric on both axes, so I only modeled 1/4 of it. I then duplicated the elements and reflected them a few times to get the full part. But, it looks like the elements are still 'separate'. I could join them with a contact surface, but I'm afraid that may skew my thermal analysis that I'm doing on them. How do I combine these 4 different 'quarters' of my mesh to be one single mesh? Or if there is a way to designate perfect contact for steady state, please let me know.