Composite testing
Just as a general reply to all the non-composite experts and non-stress engineers.
Yes, when we test composites we artificially age and damage test pieces. We also typically test in a hot wet condition (humidity in particular has a negative effect on the structural properties of CFRP).
Can we all stop making out that the engineers (i.e. me) have no idea how to design composite structures. After 20 years of design and testing we do.
The rudder failures that so many of you are so excited about were design failures not composite problems. My point being that ingress of hydraulic fluid requires something to leak the fluid on to the composite.
And finally, whoever it was that brought up that some manufacturers say composites are no good. This will probably be because they are not capable of manufacturing composite primary structure. Airbus was saying that composite fuselages were a bad idea, right up until they canned the old A350 program and restarted with a composite fuselage.
Can I please ask that anyone writing a post that begins with the phrase "I'm not an expert" dosn't. There are a lot of experts on this forum but it's annoying to have to trudge through the wild speculation to find the interesting/insightful comments.