If, and that's a big IF, you can make a rim fail, that will be a FIRST.</p>
AFAIK, no rim has failed before the rubber. I'm not an engineer (or lawyer) so take this with a grain of salt but I don't think you can bend, break or even put a dent in a rim due to weight. Now, if you go humming along at full speed and hit a railroad iron when you have low tire pressure, you may be able to damage a rim.</p>