Happy Halloween!
5E8F74B9-EED9-49E5-B2C8-508EC10D41B1 by
Richard Mozzarella, on Flickr
Zombie thread, indeed.
The guys in Formula 1 racing do deflection tests on their composite parts. The purpose is to Suss-out the added flexibility of the 100's of thousands to millions of tiny micro-cracks in the resin matrix that cumulatively lead to a part no longer performing as designed.
For this to work, you need a reference point. This is usually the logged test results from the very first time a newly manufactured part is put in a test rig to be tested. As a part is put in service the micro-cracks accumulate & this is revealed by increased flexibility (deflection) under test load during periodic testing.
Carbon fiber doesn't assplode. It tends to fail gracefully. With careful examination the damage is detectable & actionable.
What we're talking about here is mode of fatigue failure. Steel, Aluminum, Titanium tend to fail at some stress concentration & then concentrate at the concentration.
Like so many other things, it's down to design & execution.
(...and of course catastrophic failure is by definition: catastrophic. This comes from exceeding engineering designed capacity. That's not a question of material, that's a question of designed capacity. Take that up with the parts engineer.
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