Armor, part II

[targon]

I have just read previous Armor thread. Lots of ideas, but most a simply unreal.
I'm not a military, but I do know something about real armour technology. In short: the "thicker is better" is from 19-mid20 century.
Then projectile strikes armor, shock wave develops. Its strength (pressure) depends on equations of state of both projectile and armour. The rule of thumb: the denser the materials are, the more powerfull wave will be.
If projectile is fast enough (>~3-5 km/s), pressure in shock wave will "dissolve" armour (armour will act as it would be liquid). Then, penetration depth may be easily estimated as *sqrt(/ ).
Shock wave will suffer decrease from back-moving unloading wave with rate of ~1/.
When reaching next free surface, shock wave may (_will_, in real) create spalling, creating spray of fast-moving (if both projectile and armor is of same material and we'll forefit pressure extinction, velocity will be the same as projectile's). This particless will destroy equipment, detonate load and kill unfortunate staff).
Particle beams are more fun. They penetrate some depth in armour, creating "energy deposition zone". In this zone pressure rises almost instantly, proportional to specific energy density, with coefficient known as Gruneisen constant.. This presure forms shock wave and viola - spalling.
So, absorbing layer of armour must be either dense, tough and thick to survive, or use some nasty tricks of trade:
1. Layered armour: the idia is that spalling particles are "weaker", more spread, so _next_ layer of armour may be more lucky. There must be some free distance between layer, of course. This thing is used in russian T-80, if I corretly remember.
2. Armour may be very energy-hungry, eating energy from shock wave. One clue (my own idea): porous medias actualy transfer much more energy from shock wave to harmless heat, then their pores collapse.
3. Against beams, armour must have less possible Gruneisen in the world. In general, plastics have less than metals (~1 and ~2)
4. Against beams, high-Z materials as lead, tungsten or depleted uranium ase 100% help for attacker, as they will have much better energy density in deposition zone
5. Long (several nanoseconds) laser pulses are futile against armour, as expanding corona of superheated plasma blocks laser beam - completely. Anyway, modern lasers are very inefficient creatures, with extremly low efficiency coefficient (ranging from 15% (CO2 lasers) to 0,1% or even less).
Much others - realistic suggestions?
IMHO, any way of field armour repair will be fruitless. Units are highly unlikely to survive successfull hit, they may be more stealthy instead. Any modern carier may be sinked with single anti-ship missile with high probability.
P.S. Concerning shielding. Can't say much, but cummulative stream may be efficiently dispersed if armour is magnetized (around 1 Tesla, which is dramaticaly big and surely make all on-board circurity insane). Any early interruption of incoming "agressor" (beam or projectile) is also much help.

[targon]

Damn that web interface, it garbled formula I just wrote. Penetration depth is estimated as:
(length of projectile) * sqrt((projectile density)/(armour density))

[DeathByTheSword]

well i wont disagree with you on all of this....but:

**missile can be shot down these days....you have the goalkeeper system that fires several rounds in a short timespan that well shoots down the missile....

**many modern day tanks use reactive armor...i think the russians invented it.....it is consists out of several blocks that are put all over the tank....the block is 2 sheets of metal with some explosive in between...it a projectile hits such a block it will = hit the first metalplate this in will try to slow the projectile down...because of the pressure and the heat of the projectile against the first plate the explosives between the two plates wil detonate. this will slow the projectile down some more. the last metal plate will be push against the tank it self and reflect.....it will crash against the projectile and it will be destroyed.....it is a one time use...but what if in the future you can make armor that has several of this kind of layers....?


and what if you can build metals in a way that they have a hexagonal structure.....this structure will let our upper legs withstand 1,5 tons (Kg) of weight......?

just some ideas

[targon]

** Penetration of any anti-missile system is matter of sheer number of incoming warheads. So-called "Phlanax" system is nice stuff until it have to track multiple contacts.
** Reactive armor was in fact designed against cumulative warheads. Cumulative round consist of HE explosive with conical shell covered with some "heavy" metall (russians usualy prefer copper, americans sometimes employ uranium). This relative thin film may be accelerated to velocities close to detonation velocity (~9 km/s for HMX) and penetrate _any_ armor like knife cuts butter. Exploding round can't rotate as rotation will distrupt cumulative stream to relative harmless short pieces. Cumulative stream is to some extent unstable, especialy while moving inside "special" media. Explosive is definitely "special" and unstabilizes stream. Reactive armour is't very fit for deflecting projectiles.

Honeycomb-like structures are definitely great idea. Shock wave will crush its sections rather then do more "useful" deeds... but whis stuff must be too bulky in order to stop real copperhead.

Just one more idea: nanotech. Nanites may form zillions of acoustic "channels" which will take momentum of incoming shell and then disperse it over great surface causing reduction of pressure ~ to increase in area. Distinct "channels" must be fairly sparse in order to guide momentum separately... At work I routinely use substance called "aerogel" which are extensive 3D network of 3-5 nm sized SiO2 nanoparticles. This stuff has sound velocity of something like 50 m/s (6 times less than air... just imagine it) and eats wave energy like mad (reduces bulk speed from 500 m/s to 50 m/s via 1 cm... I think the later must be error... how media may disperse wave _such_?). If we could reproduce media of same properties and controlled structure (OK, we may do it via SP nanotech easily) it may be excellent armour and weight something like 150 g per liter...

[targon]

While StP was proclaimed as "realistic" game, nobody seems to want discuss real world armour physics. It was my mistake to start such a thread. It's too special. Hope current state of armour tech is close enough to "real world".

So, what about closing this thread?

[DeathByTheSword]

no wait this can be great stuff for anything...and i think your are just a kind of specialist that we all arent....
about the phalanx-system....
it first uses rockets to shoot down missiles (>10km) then within 5km it uses the guns....one modern day warships they only have 1 or 2 of these systems but in the future you can have enough to take on multiple warheads...and not many ships fire more then 2 missiles at another ship these missiles are way to expensive to fire 50 at one ship if only one is enough.

[Rasbelin]

Nah, I'm not going to close this thread. I think those ideas are great, and as I said previously, I do care about realism. I'll have a look at your ideas as I have more time.

[targon]

OK, thanks, I was disappointed by some apparent ignorance. Now I know it was just deep thinking. Thanks.
Phlanax is great stuff, but simple compare velocity of modern missiles (~1 km/s in atm.) with velocity of best superboosted guns (~3 km/s). Phlanax has very little time to fire back and shoting down _maneuvring_ missiles is't "fish in barrel". It's fish in fast river. And like anti-ballistic defence, this system may be fooled with fakes - cheap and numerous.
But, IMHO, point defence is one of directions of future defencive systems, as "shields" are still fantasy (we now almost know how to teleport but still out of ideas of any "force field"). This systems will be improved dramaticaly, and means of their penetration, too. Currently, american SDI have no chanses agains russian "Satana" and "Stilet" class missiles (if I correctly remember their western nicks) even under best conditions. BTW, if missile can't hit its prey, it may detonate beforehand, causing dramatic collateral damage and crippling stuff around.
Futuristic missile platforms may deploy anti-matter payloads, extremly small and deadly. ~26 g of antimatter will make as bang as 1Mt warhead does...

[DeathByTheSword]

Futuristic missile platforms may deploy anti-matter payloads, extremly small and deadly. ~26 g of antimatter will make as bang as 1Mt warhead does...

cool

problem is the production of anti-matter if we produce 100X more then we do now we will have enough for a teaspoon in about well 1000 years (or more i cant remember that) i think that (if we can build them with sufficient strenght and smaller) lasers will be the best pointdefence system around. The speed of a missile will have no affect because a laser travels at the speed of light. the only problem will be the targeningsystem. but that can be handled too. another anti-smartweapons-system will be EMP-missiles. i dont have much info about EMP but what I was thinking is this. if a missile is locked on to what ever if has electronic onboard if you can fire a rocket at the missile that unleashes a EMP-shockwave near the rocket (~500 - 1000m) you can disable the missile. it will stop every action and will fall to the ground. maybe a simple casing around the missile would be enough to stop the EMP wave. but we work around that part too

[targon]

I do know something about EMP, it really wipes out electronics. In general, this stuff consist of explosive-magnetic generator which converts energy of chemical explosion inside collapsing circuit into energy pulse of several MWt (and possible up to GWt!), then emits this pulse via emmiter. But circuits may be effectively protected by shielding (metal plating, what is). BTW, at work I use electronics near 10GWt e-beam accelerator, and simple electromagnetic shielding helps much, while computer ~30 m away routinely shuts down if it's switche on during pulse.
Anti-matter: sure, currently we can't produce much of anti-matter, but 100 years before we were unable to produce any isotopes. Who knows? Anti-matter is mirrored or almost mirrored counterpart of our matter, so matter possible may be "mirrored" into anti-matter --- without recreating AM from scratch, as we currently do.

[DeathByTheSword]

i ment EMP not ECM. me stupid and changed.

Anti-matter: if you think we maybe can produce it in the future i think you cant be as hard as you have been about the other ideas of armor. because they are all based upon thinks that might be able in the future... that was all

BTW where the heck do you work...you play with all lot of neat stuff

[targon]

Antimatter belongs to poorly known field of particle physics, while physics of shock waves is fairly well known, believe me. Newtonian physics still work at low speeds and gravity fields while it's extended bu Relativity Theory. So we can't expect something dramaticaly new in basic properties of matter.

I work at "Institute for High Energy Physics", or IHED, while stuff I play with is in place called "Russian Science Center "Kurchatov's Institute"". BTW, 20 years ago, USSR made ~30% of world's net experimental research, so there are lots of neat stuff surprisingly still working.

[targon]

Hell, IHED == Institute for High Energy Denseties. Seems I need go home... bye, people
"Basic" means "simple" here, not laying at the base or fundamental.

[targon]

Hey, I'am here today, but this can't last too long (boss nearby). So let's add some new ideas.
1. Plastics armour. Rather than withstand rigors of shock-wave loading, rubber and likewise media espand like mad then move back. Rubber need to be stretched ~600% in order to break. Recently, I did some work regarding e-beam loading of rubber, and, hey, this stuff is't easy to torn apart!
Another anamaly: unloading wave is way too fast in rubber and eats loading wave more quickly. So thick layer of rubber may dramaticaly decrease shock wave pressure and eventualy prevent deadly spalling. Wonder why this is't used in tanks ... or it is?
2. Electromagnetic armour. Consist of cells which take momentum of projectile then convert it into electricity and charge unit's battery ... this stuff still may cause EMP damage and eventualy may be overloaded by larger projectile...
3. Advanced reactive armour. Section detonates _before_ real impact, accelerating plate attached to its forward. This stuff may be easily accelerated to ~3-5 km/s, so warhead will meet hot reception

[Blake]

Here’s my idea for nanite armour (incidentally I thought of it before this thread, as I am well aware of the limitations of armour at stopping high energy projectiles - I've always said armour should be most effective against small arms and minimally effective against anti-tank weapons)

The nanites have three functions:
Produce gas (to form a foam/sponge/honeycomb like structure)
Absorb gas (to form a liquid)
Bind with other nanites (to form a solid)

Collectively these nanites can form 3 structures:
Fluid: In this state it can be stored in tanks and pumped to sites that need the armour to be replenished, ie where it has been breached or blasted apart.
Foam: To enter this form the nanites produce gas, creating many small air pockets, the foam would be quite stiff (stiff enough to support the weight of the outer armour layer), but collapse when hit by a high energy shockwave, thus absorbing much of the impact, when collapsed it would go into fluid state.
Solid: The nanites can bind into a super hard ceramic or metal like solid, this forms the outer layer of the armour, protecting the foam and deflecting small arms fire and other environmental hazards.

How the armour reacts:
When the armour is hit by a high energy projectile the outer layer is smashed or crushed, the foam absorbs as much of the shock as possible and becomes fluid, depending on the extent of the damage the fluid can either refoam and resolidifiy to immediately replace the damage - or if large amounts of the nanites where physically blasted from the armour plate a simple protective layer is quickly generated, suitable for keeping out environmental hazards.
Once in safer conditions the temporary protective layer goes into fluid mode, and more nanite fluid is pumped to the damaged location, at which point the original shape and structure of the armour is restored.

The outer layer would resist heat, and the foam would provide a degree of insulation, a high energy laser could melt the armour, but the way the armour could quickly regenerate, provided the internals aren’t damaged too badly.

Control:
Think of the armour layer as a shell, inside is the "body" of the vehicle or ship, on the outside of the body are electrodes that can generate electromagnetic fields, when properly stimulated by the field the nanites will change shape, thus ultimately a computer controls all the nanites. This does mean if the computer can be hacked the armour can be disabled (as in the nanite layer falls off), or an EMP may be able to fuse the armour into it's current state, making regeneration impossible.

In practice the outer layer could also protect from EMP, and if the nanites in the outer layer are damaged beyond repair, then they could simply be shed or absorbed. With proper security hacking should not be a threat, although IF the computer could be hacked, it would be possible to turn the machine against it's masters.

Worth noting I don’t really know if it’d work or not, perhaps stiff foam would not be the best structure for absorbing shock, perhaps if instead the nanites bonded to form something like a rubber honeycomb.