Hello,
yes it is possible because I have done it. My best recommendation is to hit the Books hard. And when I mean Books I mean the SRM, OHM, Standards Manuals, Mil-Handbooks, Etc. When working a repair you need to know where to find answers fast. Learn to use the index so you won't spend hours surfing the tape. If you have access to the DC-9/MD-80 SRM read and learn how to use Chapter 51-30-0. It will show you how to design a correctly loaded sheet metal repair with the correct number of fasteners. Learn how to read and interpret Blueprints, Engineering orders, Service Bulletins, Parts lists, Etc. Learn about configuration research and effectivity. Learn about the material strength and properties of Fasteners, Aluminum and Steels used in Aviation. Learn about the repair of Bonded and Composite Assemblies. Learn about the many processes used such as Heat Treat, all the Different types of Plating used and why. Learn all about welding and the different welding processes. Learn about machining of Aluminum and Steel.( thats a gold mine in itself ) I know I am getting a bit long winded here but a good "repair" Engineer should have a very good working knowledge of everything I mentioned above. I would not recommend taking a stress course until you have accomplished some of the above (It will give you a splitting headache). The best course of action I could recommend is to learn all you can on your own and try to find some experienced old goat in your Engineering Department to become your mentor and get you involved with repairs. Design a repair or two based on what you have learned and submit them for evaluation to your Engineer. You may be suprised at the results. Last but not least, Douglas ( Boeing FSI ) Aircraft offers an excellent "Repair for Engineer's" Course at Cypress California. ( Near Long Beach ) The Structures Course runs one week and composites runs four days. You don't have to be a card carrying Engineer....just pay for the course. I went and I believe the course paid for itself. Not only do they cover "repair" to a knats behind, they teach you how and what to submit to the OEM and or the FAA for 8110-3 Approval. I hope I have given you some hope here.......Its a long and winding road of learning and remembering. I didn't get an Engineering Degree in college, Mine was in Business, But I was pretty good in Math.......
What I have just told you was what I did. I have been doing this for 28 years and I love my job. Every day its somthing new and I love a good challange. ( plus they pay me for it )
The best advice I can give is all of the above and just approach it with the attitude that in this business you learn somthing new every day.
Best of luck
David