With carbon fiber playing such a vital role in industry today, and with super slow motion video being readily available, I am surprised that I cannot find good video of carbon fiber failure on Youtube. I would have expected to find dozens of such videos, yet the very few videos available under the search term carbon fiber failure are not great. I’d love to see various profile failures up close and in super slow motion. Is there some other good source for carbon fiber failure videos out there somewhere?
Youtube Carbon Fiber tensile test. Canyon and Riff both have videos of their testing. Nothing slow motion, just some good old fashion PaPOW!
Most ASTM testing is boring. Compression testing, all you get is a “thunk”…3-4 point bending sometimes is fun, but can take 5-10min per test! SBS is tiny, and hard to see. Tension is where it’s at. Oh, and impact.
Lemme see what I got on file.
Boring 3-point core test. Glass skins, can’t say what core 
[ame=“http://www.youtube.com/watch?v=KWlx4MIcvXU”]3 Point - YouTube[/ame]
Skip to 75% done in this one:
[ame=“http://www.youtube.com/watch?v=tTn3Qr6h-2Q”]BAM… - YouTube[/ame]
two carbon tests:
[ame=“http://www.youtube.com/watch?v=I_G2262PYrE”]Pop goes the carbon. - YouTube[/ame]
[ame=“http://www.youtube.com/watch?v=Md3OvnCZj2s”]Tension testing 2 - YouTube[/ame]
One of them was epoxy, the other PPS/AS4 I think.
Also, companies who have enough money to both pay for and have the necessity to do stress tests are companies who are making very high end stuff (i.e. Boeing, Airbus, McLaren) will keep their results confidential for obvious reasons. I have several that work for Augusta Westland, a local helicopter manufacturer that produces military units. They tell me about the voids in helicopter blades when they get X-Rayed or when they go through tension tests. After that they say “I didn’t tell you that, I’d like to keep my job”
Then again, I don’t know how much it costs to pay a company to smash a couple of nosecones, but I wouldnt want to see my carbon being blown to bits! Lol
interesting video what machine is the tension machine? it seems Galdabini tension machine that I used in my previous job
The car company I worked for smashed some crashcones, 30 of them. The intern doing the research spend a few weeks making them and a few rolls of 12K carbon prepreg. And then he spend a day crashing them
I don’t know if video’s exist , and although not military, if I had them The contracts still apply 
They are all Instrons. Not sure the model of any, except I’m SURE 4484 on the tensions.
Thanks for the videos. I had not seen any of those posted. I still wish there were some better slow motion videos, because something is bothering me about tow types.
A beam or cantilever under bending stress can fail in tension and/or compression, and most tows are marketed for their tensile strength specs., yet in fact, sometimes the compression specs. are better for tows with lower tensile strength. T300 vs T700 is a classic example of tows that have conflicting specs. Neglecting cost, the automatic choice by the vast majority of buyers might be T700, but if the end use application is going to see mostly compression, T300 is the better choice.
But back to bending and members seeing tension and compression. Given that tensile strength in a carbon epoxy composite is always higher than compression strength, this would seem to indicate that bending failure will occur first on the compression side, and if this is the case, then automatically opting for the tow with the highest tensile strength might be the wrong approach here as well. Super slow motion video of catastrophic bending failure would reveal interesting information. In any event, I thought I’d toss the idea around.
Many composite structures will buckle under compression before the ultimate compression or tensile strength is reached. The first video of the 3 point load is a great example. The top skins buckles away from the core at 0:39.
Well, that is more of a “core” type flex test. The outer skins were glass, and the inside was a thermoplastic UD fabric. But you have a lot of shear at timees, and like always, it depends on everything…the layup, the material, and the real-life forces the part sees.