Better than the house spinning.
Both heat and UV radiation can damage the resins used in composite materials through oxidation over time. I would assume they select resins that minimize the effects for parts designed to be exposed outdoors for their entire life cycle. That doesn’t make the issue go away from we are looking at life cycles measured in decades.
Not universally, since (1) the technology is changing so fast, (2) a blade design is specific to the tower height and the characteristic wind-speed. I imagine that when you are talking about wind farms with hundreds of towers they must pretty much all be identical.
No, it doesn’t. Not even a little bit. And statics is irrelevant to this discussion.
You’re thinking of plastic deformation. Fatigue always happens in plastic deformation. It can happen during elastic deformation, but it doesn’t have to.
That’s true, but it’s not what I said. Besides, you’re conflating strain with fatigue. They’re not remotely the same. If you had retained what was taught in mechanics of materials, you wouldn’t have this problem.
I wouldn’t come down on you so hard if you hadn’t done that handwaving about “this is just a question of where we draw the line.” These are not judgement calls; they’re basic materials science concepts. Birds aren’t mammals no matter where your pencil has wandered off to or what line it drew when it got there.
Steel and titanium have endurance limits. Strain below their respective limits does not accumulate fatigue. Aluminum has no endurance limit, so any strain—no matter how small—adds to the cumulative fatigue in the structure. This sounds alarming, but it’s not: with proper design parameters, an aluminum structure can have an arbitrarily long fatigue life.
Fatigue in composites is complicated and not fully understood, but we know enough to design reliable composite structures—at least, those of us who paid attention in class do.
This is solipsistic. There’s nothing that won’t be damaged if you bend it too far. That’s the very definition of “too far.”
Whatever. We are using different sets. As ai said, my schooling was different than yours.
I owe you a partial apology. My penultimate sentence was meant to read, “Fatigue in composites is complicated and not fully understood, but we know enough to design reliable composite structures.” That line instead contained a gratuitous barb that I thought I had edited out before posting. Obviously, I was wrong. I’m sorry I missed that.
Well, yeah. We call it “erosion”. It turns mountains into little rock stubs. Given time. Time, and pressure… that’s all it takes, really. I’m sure I’ve heard that somewhere 
At Ep: Left hand is not working now, so I keep posts shorter than is best.
No worries, NO acrimony, We Are OK. I understand your points.
That’s interesting, I didn’t know that and it seems a little counterintuitive - it was my understanding that wind was caused by pressure differentials and interactions between cold and hot air masses - but air masses gets hot (or not, hi 1996 !) during the day when the Sun cooks this bit but not that bit and so on ; so why more wind at night ?
Cool. I hope your hand feels better pronto.
Round here we get 40-50 mph windstorms in day. Things calm at night.
What .you get depends on topography.