Hey /sci/,
So as part of a lab I pictured a piece of unidirectional CFRP in a scanning electron microscope. Only thing is I got a strange pattern of tensile and compressive failure (picture included).
What global loading could lead to this failure pattern? Any help is greatly appreciated.
>>7912040
>asking questions about the actual practice of science
>on /sci/
I think you've misunderstood where you are. Please restate your question in the form of a shitpost.
>>7912262
I'm just asking in an attempt to understand what's going on. I couldn't find anything similar anywhere online so was just hoping that somebody on here had seen something similar.
>>7912299
okay then let me do your homework you lazy scum
let me first say that I have zero education on this. I even had to google what CFRP is and how a scanning electron microscope works
one of the first results on google:
http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392010000300022
dumb idiot
>>7912040
>pattern of tensile and compressive failure
OP try drawing on your SEM image with arrows to highlight the areas you are refering to.
I'm an experienced microscopist but composites aren't my forte
>>7912327
>I'm an experienced microscopist
lol
again, I don't know anything about this kind of stuff but it seems obvious the hairy regions are tensile failure and the flaky regions are comressive failure
>>7912324
The fact that you have zero education in this is evident given that you've linked an image unlike mine. I could tell you that was a bending test with my eyes closed you fucking retard, so before accusing me make sure you aren't making an ass of yourself.
>>7912334
>compressive failure
This sounds like bullshit to me. How can it fail in both tension and compression at the same time. Compression would cause a 45 degree shear fracture not a flat horizontal
>>7912352
By bending
>>7912350
yeah okay
I am sorry
I acted like a retard. has been a long day and I only got 4h of sleep
anyway... yeah obviously the pattern is not the same. but what was written in the thing I linked is that compression outweighs tension
so how about bending it in one direction, the two outer layers appear, then bending it in the other direction and the two inner layers appear? something like that possible? on the top of my head nothing comes to mind that would cause tension compression pattern in 1 movement without there being different layers of material involved. so my guess is there was more than one movement involved
but hey, maybe I should just shut up now
>>7912421
It's aight, same thing here, no hard feelings. Yeah that's exactly what I was thinking too actually, but there seems to be little research out there on it. Either way, the fact that you think this might be the case is definitely a good sign, so I'll probably go with it because just purely intuitively I can see literally no alternative. Cheers for the input
>>7912448
yeah, sorry again. I feel like a shithead now. I'm glad it seems I could at least make up a little bit for it
I hope everything goes well for you, see ya
>>7912040
>CFRP
What does that mean?
>>7914162
it means you should go to google rather than shit up the board by bumping dozens of threads from page 10 with idiotic replies
>>7912040
It's because there's a sandwich in the way.
>>7912262
Where do you do homework from lab work??
>>7912040
>unidirectional CFRP
It appears that there are 4 layers, each layer having unidirectional CFRP 90 degrees on the neighbouring layers.
So where we actually see the bristles of the unidirectional CFRP it seems simply cut with a knife or scissors. Even after bending multiple times it is hard to imagine all would be cut at the same distance.
Where you do not see the bristles sticking out there are bits missing, probably pulled out. The fibres do not provide reinforcement across the fibres only along so nothing prevented chunks of material from being pulled out after being crushed by the knife/scissors.
