Originally Posted by jackpiner57
That's some brilliant thinking Tim. I believe you're right about the resonant harmonics having a lot to do with stress cracking. It just makes a lot of sense.
I wish I could take credit for brilliance, Tom. I was recently reading an article by some guys who were developing a new kit-built aircraft which gave me the idea. Resonance was a huge problem for them. They were using a welded chrome-moly steel for the airframe, which is similar to the tubing on the racks. They were suffering failures at certain welds no matter how much they reinforced the structure. It turns out their solution was to make things more flexible, not more rigid.