Steve Jackson Games - Site Navigation
Home General Info Follow Us Search Illuminator Store Forums What's New Other Games Ogre GURPS Munchkin Our Games: Home

Go Back   Steve Jackson Games Forums > Roleplaying > GURPS

Reply
 
Thread Tools Display Modes
Old 10-12-2015, 05:26 AM   #1
Anders
Banned
 
Anders's Avatar
 
Join Date: Jan 2005
Location: Gothenburg, Sweden
Default Catastrophic failure of armor

So if I understand things correctly, armor tends to protect very well or suffer catastrophic failure and protect very badly. If that is correct, wouldn't a good model be that DR either protects fully or (if any damage penetrates) gives DR 1 or 2 if it fails. Would that make sense?

Edit: Apparently I was wrong. Move on, nothing to see here.

Last edited by Anders; 10-12-2015 at 03:10 PM.
Anders is offline   Reply With Quote
Old 10-12-2015, 06:15 AM   #2
Ji ji
 
Ji ji's Avatar
 
Join Date: Feb 2012
Default Re: Catastrophic failure of armor

Quote:
Originally Posted by Anders View Post
So if I understand things correctly, armor tends to protect very well or suffer catastrophic failure and protect very badly.
Can you explain this point? Which sources are you referring to?
Ji ji is offline   Reply With Quote
Old 10-12-2015, 06:28 AM   #3
panton41
 
panton41's Avatar
 
Join Date: Jul 2005
Location: Jeffersonville, Ind.
Default Re: Catastrophic failure of armor

Quote:
Originally Posted by Ji ji View Post
Can you explain this point? Which sources are you referring to?
At least in the modern day I know that for the most part bullet resistant armor either stops the bullet completely, or it penetrates and does nearly full damage, with little in-between.
__________________
The user formerly known as ciaran_skye.

__________________

Quirks: Doesn't proofread forum posts before clicking "Submit". [-1]

My ebook page.

Quote:
"My mace speaks Goblin." Antoni Ten Monros
panton41 is offline   Reply With Quote
Old 10-12-2015, 07:43 AM   #4
Tomsdad
 
Join Date: Jan 2010
Default Re: Catastrophic failure of armor

Douglas Cole has a system that gives you this on his Gaming Ballistic blog
Tomsdad is online now   Reply With Quote
Old 10-12-2015, 08:05 AM   #5
Varyon
 
Join Date: Jun 2013
Default Re: Catastrophic failure of armor

Quote:
Originally Posted by Tomsdad View Post
Douglas Cole has a system that gives you this on his Gaming Ballistic blog
If you don't want to use Armor as Dice, an alternative is to simply divide DR by 3 (round down) on a penetration, which functions about the same as that rule. Quadratic schemes, where you square the damage and DR, find the difference, then use the square root of that, have been proposed before as more realistic alternatives, and IIRC the divide by 3 rule ends up with fairly comparable results and is much faster.
Varyon is offline   Reply With Quote
Old 10-12-2015, 08:12 AM   #6
Ji ji
 
Ji ji's Avatar
 
Join Date: Feb 2012
Default Re: Catastrophic failure of armor

Quote:
Originally Posted by panton41 View Post
At least in the modern day I know that for the most part bullet resistant armor either stops the bullet completely, or it penetrates and does nearly full damage, with little in-between.
I wonder if this applies to muscle powered weapon or not, given the huge difference in speeds involved.
Ji ji is offline   Reply With Quote
Old 10-12-2015, 08:33 AM   #7
Tomsdad
 
Join Date: Jan 2010
Default Re: Catastrophic failure of armor

Quote:
Originally Posted by Varyon View Post
If you don't want to use Armor as Dice, an alternative is to simply divide DR by 3 (round down) on a penetration, which functions about the same as that rule. Quadratic schemes, where you square the damage and DR, find the difference, then use the square root of that, have been proposed before as more realistic alternatives, and IIRC the divide by 3 rule ends up with fairly comparable results and is much faster.
nice, good point!


Quote:
Originally Posted by Ji ji View Post
I wonder if this applies to muscle powered weapon or not, given the huge difference in speeds involved.
Apparently not, I'll be honest I've still get questions about the real life mechanisms it's referencing, but it does seem to be a bullet vs. ballistic cloth thing. There was recent thread that touched on it a bit.

Last edited by Tomsdad; 10-12-2015 at 08:46 AM.
Tomsdad is online now   Reply With Quote
Old 10-12-2015, 10:23 AM   #8
The_Ryujin
 
The_Ryujin's Avatar
 
Join Date: Jul 2012
Default Re: Catastrophic failure of armor

Quote:
Originally Posted by Anders View Post
So if I understand things correctly, armor tends to protect very well or suffer catastrophic failure and protect very badly. If that is correct, wouldn't a good model be that DR either protects fully or (if any damage penetrates) gives DR 1 or 2 if it fails. Would that make sense?
This sort of catastrophic failure only really happens with Kevlar and cloth style armor. Basically if the bullet hits with enough energy to exceed the strength of the fibers then they can't "catch" the bullet. In that case the only energy lost by the bullet is the energy needed to break the fibers in which case a DR of 1 or 2 per 10 points of DR the armor has seems about reasonable though keep in mind I'm not an expert here on this subject heh.

IIRC, DouglasCole used to work with Kevlar before and has done experiments on the failure models for it so hopefully he'll be able to chime in on the matter.
__________________
"Conspiracy theorist": Because people who show the evidence known lairs *GASP!* are lying must be crazy >.>

Guess I should hawk by blog here: http://gurb3d6.blogspot.com/
The_Ryujin is offline   Reply With Quote
Old 10-12-2015, 12:23 PM   #9
Desthro
 
Join Date: Nov 2009
Location: Albuquerque
Default Re: Catastrophic failure of armor

It's all about how much energy the material can absorb and disperse over that fraction of a second during impact without failing immediately. If the kinetic energy on impact doesn't exceed that value (whatever it is), then the projectile is stopped as the weave is able to absorb the kinetic energy over a much broader area. If it goes above that threshold, the fibers in that area get destroyed immediately and are unable to disperse the energy of the projectile which results in penetration. It seems like more of a material design problem (using a weave as opposed to solid plates of the material) than an actual material weakness problem.

I'd imagine that slower projectiles are less likely to meet this threshold as the weave has a larger time frame to absorb and disperse the kinetic energy from the impact. Faster projectiles should be more likely to penetrate as the material has a much smaller amount of time to achieve the same thing. I could be wrong here too, as I am not an expert.

I wouldn't be surprised if wounding has a similar profile as well.
Desthro is offline   Reply With Quote
Old 10-12-2015, 12:28 PM   #10
Anthony
 
Join Date: Feb 2005
Location: Berkeley, CA
Default Re: Catastrophic failure of armor

Quote:
Originally Posted by Ji ji View Post
I wonder if this applies to muscle powered weapon or not, given the huge difference in speeds involved.
Depends on the attack type. On a thrust with an impaling weapon, if the tip doesn't get stopped by armor, you can apply continued force after penetration to continue driving through almost indefinite amounts of flesh. On the other hand, against cutting and crushing it's almost more accurate to treat the armor as a damage divisor.
__________________
My GURPS site and Blog.
Anthony is offline   Reply With Quote
Reply

Tags
armor, damage resistance

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Fnords are Off
[IMG] code is Off
HTML code is Off

Forum Jump


All times are GMT -6. The time now is 07:10 AM.


Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2018, vBulletin Solutions, Inc.