Making Mac OS X split .rar files available to non-mac users

I've split a 8 GB my_doc.rar file into 4 separate files using the following command from my Mac OS X 10.9 terminal

split -b 2000m my_doc.rar my_doc.rar

After splitting the file I've generated: my_doc.raraa, my_doc.rarab, my_doc.rarac, and my_doc.rarad. Can I make the 4 files .rar just by removing the extensions? No, because I tried to extract those using UnRarX by renaming as my_doc1.rar instead of my_doc.raraa, my_doc2.rar instead of my_doc.rarab and so on but it didn’t work! Then how other people would be able to join those using software like WinRaR or UnRarX? Aren’t the generated files .rar files? However, I know I can join those on my Mac by using cat like this:

cat my_doc.rar* > my_doc.rar

But how would I be able to share the big file with people who don’t use a Mac?