Cracking vs Fragmentation vs Explosive Fragmentation

[TioKill]

This doesn't need to be an incredibly well planned CRT - the problem of the matter is very straightforward.

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Let's look at this

Yeah, you read that right. All these three forms of - well, "fragmentation" - are attributed to the same value of 8 joules per cubic centimeter (for concrete). I get this is done due to simplicity sakes, but this often wanks or downplays low tier character - and doesn't represent the true strength displayed.

Let me put these levels of fragmentation into words first.

Cracking: This refers to the aftermath where the material is left at the state close to fragmentation, some pieces can fall off, but mostly, the object is structurally stable depending on the weight.

Fragmentation: Breaking a material into sizable chunks.

Explosive Fragmentation: Breaking a material into sizable chunks - where the impact is strong enough to launch these chunks away.

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Let me propose the following solutions for the two alternative levels of destruction.

For cracks, we use the tensile strength of the material - for concrete, that's 5.5 J/cc. Tensile strength, as you know, is the amount of tension a material can receive before it breaks. Seems reasonable enough.

Explosive Fragmentation is a little bit tricky, but for concrete, I've found this source that says the impact has to carry 15-20 J/cc.

 

[It_is_i_wyatt]

im not knowledgable on this at all but it seems like a good idea to differentiate these

 

[TioKill]

im not knowledgable on this at all but it seems like a good idea to differentiate these

Yes.

 

[Shmeatywerbenmanjenson]

Good job Tio glad to see you addressing this.
This has been a problem on the wiki for far to long

 

[Tatsumi504]

Following

 

[KLOL506]

8 J/cc is... not for concrete. 8 J/cc is for actual rock.

Tensile strength is pulling strength. Concrete's low-end frag is 6 J/cc. But its v. frag on the other hand, is actually 17-20 J/cc, which actually lines up with your explosive fragmentation value. 17 J/cc is high-end shear strength and 20 J/cc is low-end compressive strength.

Also this thread exists and has... well... even more insane values for other forms of rock for explosive frag. Though it only applies to actual explosions and hypervelocity impacts at ablation speeds and re-entry speeds. And yet it never went anywhere.

Also we do not allow "cracking" feats to qualify for frag, like, at all. The middle feat is what we constitute as frag and the feat on the right is v. frag. As it should be.

Crack propagation is wildly unpredictable and thus incalculable.

 

[TioKill]

Also this thread exists and has...

Uhm, so... Funny thing.
I thought concrete and rock were the same thing - English not me tongue, y'know? Neeevermind all that.

well... even more insane values for other forms of rock for explosive frag. Though it only applies to actual explosions. And yet it never went anywhere.

My explosive fragmentation value is for rocks. That is very weird, any impact that results in an explosive response should be attributed to the 15-20 j/cc or more when it comes to fragmentation. Although it's probably not going to make an official change, is it okay to use these sources and apply these values on calculations?

Also we do not allow "cracking" feats to qualify for frag, like, at all. The middle feat is what we constitute as frag and the feat on the right is v. frag. As it should be.

It's just explosive fragmentation, the visuals are not scaled to accuracy, the chunks of the e. frag should be as big as the normal frag - I just couldn't find a nice png.

Crack propagation is wildly unpredictable and thus incalculable.

Well, CGMs just approve calculations that do calc cracks and apply the fragmentation values - which boosts the result by a margin. This can be found in somewhat relevant verses like HxH.

 

[KLOL506]

Uhm, so... Funny thing.
I thought concrete and rock were the same thing - English not me tongue, y'know? Neeevermind all that.

Been a while since we changed that, a year or two now.

My explosive fragmentation value is for rocks.

So this is just for violently launching large fragments then? And not reducing them to smaller fragments? Which would leave v. frag untouched since that relies on high-end shear strength or low-end compressive strength.

That is very weird, any impact that results in an explosive response should be attributed to the 15-20 j/cc or more when it comes to fragmentation.

When you go hypervelocity, very weird things can happen where it exceeds even the frag strength of depleted uranium armor frag.

Although it's probably not going to make an official change, is it okay to use these sources and apply these values on calculations?

Not without initiating a massive sitewide revision. And especially not without finding these values for other materials like metals and wood first and foremost. Especially metals.

It's just explosive fragmentation, the visuals are not scaled to accuracy, the chunks of the e. frag should be as big as the normal frag - I just couldn't find a nice png.

Ah. So only normal frag, v. frag would remain unaffected then because it relies on high-end shear strength and low-end compressive strength due to having to reduce the object to smaller fragments.

Well, CGMs just approve calculations that do calc cracks and apply the fragmentation values

Then they're doing something wrong. I've evaluated and rejected many calcs involving just cracking and not... shattering the actual thing. Many others have done the same since then.

- which boosts the result by a margin. This can be found in somewhat relevant verses like HxH.

Then it shouldn't have been accepted. We are not supposed to apply frag to merely normal cracking of small scale where the object doesn't fail.

 

[TioKill]

Then they're doing something wrong. I've evaluated and rejected many calcs involving just cracking and not... shattering the actual thing. Many others have done the same since then.


Then it shouldn't have been accepted. We are not supposed to apply frag to merely normal cracking of small scale where the object doesn't fail.

When it comes to walls, does the rule still apply?

 

[KLOL506]

When it comes to walls, does the rule still apply?

Yes. If the wall only suffers superficial cracks and no fragments are seen flying or falling off, it cannot be frag.

Cratering walls is a different story. That's blatant compressive strength.

 

[Shmeatywerbenmanjenson]

So this is just for violently launching large fragments then? And not reducing them to smaller fragments? Which would leave v. frag untouched since that relies on high-end shear strength or low-end compressive strength.

This is mainly what I'm advocating for.
There is a significant difference between reducing a structure to rubble with a punch and reducing a structure to rubble and launching said rubble at high speeds.
A big enough difference that I believe a value between fragmentation and V. Frag is warrantable.

 

[KLOL506]

This is mainly what I'm advocating for.
There is a significant difference between reducing a structure to rubble with a punch and reducing a structure to rubble and launching said rubble at high speeds.
A big enough difference that I believe a value between fragmentation and V. Frag is warrantable.

Well, like I said, you would need to find this value for every single other material first, like metals and wood, and you would need approval from our current calc members to get this through.

Or really, you need approval from DontTalkDT and Executor_N0.

 

[Shmeatywerbenmanjenson]

Well, like I said, you would need to find this value for every single other material first, like metals and wood, and you would need approval from our current calc members to get this through.

Or really, you need approval from DontTalkDT and Executor_N0.

I would be willing to do that, It'd just take a while

 

[KLOL506]

Tensile strength for cracks however, is a big no. Cracks in general are just uncalculable due to their sheer unpredictability. That and tensile strength is for pulling feats.

 

[Shmeatywerbenmanjenson]

Tensile strength for cracks however, is a big no. Cracks in general are just uncalculable due to their sheer unpredictability. That and tensile strength is for pulling feats.

Yea, I agree cracks can take a backseat.

 

[KLOL506]

Actually, wait

This is actually the same exact thread as this one. Same exact sources and links. What the hell.

 

[KLOL506]

So ultimately, this proposal falls under the issue of having to actually figure out the speed here as well. Since the source is about hypervelocity impacts after all.

 

[Shmeatywerbenmanjenson]

Actually, wait

This is actually the same exact thread as this one. Same exact sources and links. What the hell.

Maybe we should boost that one then

 

[KLOL506]

Maybe we should boost that one then

Best to just shift the discussion there instead, as this thread would be redundant.

DT is currently on school work but I can try contacting him on the thread instead.

 

[Shmeatywerbenmanjenson]

Best to just shift the discussion there instead, as this thread would be redundant.

DT is currently on school work but I can try contacting him on the thread instead.

Got it, go ahead and just let him know we are restarting an old thread

 

[KLOL506]

In the meanwhile, you can ask a mod to close this thread.

 

[KingTempest]

I'm here, closing