Definitely needs grinding down for cleanup and a good tig welding.
This should not cost much at all. I would think less than 50 dollars which is about the same effort you will put into a bracket attached to the frame that will probably leave you wishing that you would have paid the 50 bucks..
But, I am certain that ANdy will jump in and tell you that somethin is causing this seperation such as wheel balance, sagging or maybe even slamming the door due to inproper fit.
Any way the point is, there is something else going on and it will happen again.
Sorry to be the bearer of bad news. Good luck!
Smily