Load testing wings & winglets:
This page http://www.cozybuilders.org/Canard_Pusher/RAF_LE-Structural-Test.pdf describes (with pictures) a static load test on a Vari-EZ wing, canard, and winglet.
While the Vari-EZ wing is somewhat different from the Cozy, and quite different from a blended Cozy winglet, this would be a good starting point for learning how to set up and test a modified winglet.
This particular canard failed at only 8.4 g's, which was much less than the often [mis?] quoted 12gs. Why did at fail at a lower limit? Probably builder technique, which goes to show that even if the modified design, layup schedule etc... is good, variances between builders can have a big impact on the strength of the part. I've heard some advice on adding a 2.0 safety factor to homebuilt designs to account for those variances.
But bear in mind -- this is a static, ultimate load test. We simply don't have the equipment neccessary to conduct dynamic load tests on wing structures. That's what the test period is for, I guess...
For those that care, in the next month I'll post pictures of the static load test of my modified composite "A" fram seat-back, which is intended to meet the FAR 23 seat / harness requirements. The test rig is proving to be quite the design challenge -- I've had to re-build a 18" fuselage cross section to attach the seatbacks into. Fun!
If anyone has a line to where I can get lead shot bags cheaply, please let me know!