Do you mean this paragraph? Nevermind, the quote just doesn’t show up in the document and I won’t check 170 pages to see if it just didn’t get recognized.
https://www.sciencedirect.com/science/article/pii/S2214914723001186
’ Moreover, each sequence of the distinct materials, properties and mechanical impedance are significantly important for the performance of the whole structure. Consequently, each of the different laminate has an important role towards preventing projectile piercing of the armour. The two frontal laminates (face sheet and strike face) fragmentate and mitigate the projectile’s nose. The two rear laminates (intermediate and back plate) hold the frontal plates, stop their fragments and absorbs ∼40% of the projectile kinetic energy. Hence, the strike-face should have high hardness and compression strength to break the tip of the projectile and the face-sheet should contribute to the spall protection, from spalls created by the strike-face fragmentation, on the front of the armour and to hold the strike face in position after the impact of a projectile. The subsequent laminates (intermediate and backplate) should have high toughness and energy absorption, to absorb a significant amount of energy during the impact of the projectile, while the third laminate has a great tensile strength to hold the strike-face’s fragments and protect the contact between the strike-face and the backplate. The back plate of common composite protection system is usually made up of a high-density material, especially metals, thus contributing the most to the total mass of the armour system. This research focuses on the reduction of the mass of the backplate and overall composite armour system, through the utilisation of ultra-light weight materials as backplate. The proposed materials is a Metal Matrix Composite (MMC) reinforced by nanomaterials which is designed and manufactured with enhanced mechanical and ballistic properties.’
’ 2.2.2.1. First laminate: face-sheet
The first laminate (face-sheet) is used for the spall protection, after the projectile impact preventing the micro damage to the following strike-face, protection from possible damage associated with system vibrations, protection from various environmental factors (i.e., thermal stress, ultraviolet radiation) and low Radar Cross Section (RCS) signatures. The basic functional requirements for the face-sheet layer are high dynamic stiffness, high-speed inelastic resistance to deformation, high compressive strength, and desirable hardness. These requirements contribute towards the main function of the strike face which is the mitigation of the projectile’s nose and/or the fragmentation and high shear strength due to the shearing behaviour of the material.’
’ 2.2.2.4. Fourth laminate: backplate
The backplate (last laminate layer) is used to absorb the projectile’s remaining kinetic energy through the plastic deformation mechanism, provide structure support to all of the protection laminate, and act as a load bearing element during the post impact period after the damage have taken place in the strike-face, support the strike-face body post-impact fracturing, and deform during the impact and recovery stages producing a high bending recovery and reaction. The backplate basic functional requirements are high toughness (rupture), high flexural strength, high bending stiffness, high fracture strength, suitable thickness (thin plates fail in tension due to the lack of structural rigidity), in-plane and through-the-thickness ductility (since this layer should be in deformation correspondence with the intermediate plate) and support the intermediate layer to avoid surpassing its bending strength under the projectile impacting. The backplate is a very important laminate of the composite armour since it absorbs up to the 40% of the kinetic energy.
Ductile materials, such as metal and polymer fibre composites, are ideal for use in the backplates. Metals are the most common material used for backplate due to low brittleness compared to polymer fibre composites.’
This has already been covered. Spall liners can mitigate spall even between layers, and yes, even metal can act as a spall liner.
https://www.sciencedirect.com/science/article/abs/pii/S0272884221013158
'Results showed that the UHMWPE laminate was beneficial for attenuating the damage state of back face and placing the UHMWPE laminate at the bottom core layer could significantly improve the performance of panels under the combined loads. Chocron et al. [15] developed a simple one-dimensional analytical model to consider the deformation and the erosion of the projectile, and studied the ballistic impact response of ceramic/composite armors. As the support plate of the front ceramic layer, the composite plate could restrain the fragmentation failure of the ceramic plate induced by the brittle failure and absorb the remaining kinetic energy of the projectile [16]. The investigations into the effect of the reinforcement type of back laminates on the ballistic resistance of ceramic/composite armors were carried out experimentally and numerically [[17], [18], [19], [20], [21]]. Nayak et al. [22] conducted experimental studies on the ballistic performance of ceramic-faced aramid laminated composites. For the same target thickness, the composite armors with the twaron-polypropylene back laminates exhibited a higher ballistic limit. The numerical work conducted by Tepeduzu and Karakuzu [19] revealed that the ceramic/composite structures with the aramid/epoxy backing plate showed better ballistic performance than the ones with S2 glass/epoxy or carbon-aramid/epoxy backing plate on the premise of the same area density. Moreover, related researches show the improvement of ballistic performance is available through the combination of different materials as the back plate of composite armors [[23], [24], [25]]. Liu et al. [26] examined the effect of different backplates on the ballistic behavior of the ceramic/composite armors. The results suggested that the composite armor with the backplate of Ti6Al4V/UHMWPE/Ti6Al4V absorbed a large amount of impact energy and showed better ballistic performance during the impact process. The ballistic performance of composite structures depends on not only the intrinsic properties of the materials but also on their spatial arrangement [24]. Changing the ceramic arrangement [27] or employing the ceramic layer [28] as the back plate of the composite material are demonstrated to be effective ways to further improve the ballistic performance of composite armor. Besides, the effect of mass allocation on the ballistic performance of two-component armors was investigated numerically [29] and analytically [30,31]. The results showed that the ceramic layer had a significant effect on slowing down the projectile in cases of targets with a constant areal density. Moreover, an effective methodology was developed for the optimum design of two-component armors.
In the present study, a new multi-layered composite armor with two metallic face sheets and a hybrid SiC/UHMWPE core was proposed. The ballistic behavior of the proposed composite armor against the flat-nosed projectile impact was investigated experimentally and numerically. At first, a series of experiments were conducted to evaluate the ballistic limit and to identify the typical failure modes of the composite armor. Then, a three-dimensional numerical model was established to analyze the effects of the ceramic layer placement and the mass allocation between the ceramic layer and UHMWPE layer on the projectile velocity response and energy absorption characteristics.’
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Ok. Then how does body armor work? Go watch a video of SAPI plates being shot, it literally catches the spall inside the armor before penetration. Youtube level 4 ceramic armor testing. Look up RMA 1155 testing.
What hes saying and you people are failing to understand is that western spall liners arent some shitty hung carpet, theyre real ceramics, (which is a term for composites), i.e hard layer, brittle layer, soft layer, brittle layer, hard layer. Its a multi layered system. That’s how real effective ceramics work. Or there UHMWPE, which is a lighter equally effective version
Lookup up Tensylon, lookup DUPONT. One of the pictures he posted is essentially modular Tensylon armor that bolts into things like the MRAP or Challenger 2.
So if sources say the abrams has spall liner, (NOT kevlar liner), then it very likely is a composite or something behind the bulkhead.
Theres more than one type of “spall liner”. I think the inception of what the russians are doing is not novel, and also extremely ineffective. The “spall liners” in the T90M would hardly do anything, those stupid plastic buckles would shear off on penetration and you just get smacked by a blanket full of shrapnel
Hell the M60s had internal kevlar lining and it was significantly better than what the russians are now just doing in the T90M
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‘(e) Spall liners; (ballistic cloth) should be provided to
minimize injury in the event that the tank is hit. (Note that no current tanks have spall liners; the proposed XM-1 does.)’
In this document that states the XM1 has spall liners and that the limited production run of Chryslers roughly 100 XM1s became the standardized M1 in 1981 after testing, you can see another set of requirements listed earlier.:
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But the Leclerc turret is a metal shell with composite armour bolted to the outside of it. Even if the composite blocks have an integrated spall liner to catch their all of own spall, the act of the round penetrating through the turret shell (after making it through the composite blocks) will surely create spall from the turret shell? That’s why on tanks like the Leopard 2 and Challenger 2 the spall liner is on the inside of the turret, to catch the spall generated from the turret shell and the the composite blocks on the outside of the turret.
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That is not the conclusion of those studies. If the metal is ductile enough, and especially if it’s adhered to another ballistic layer (UHMWPE, Kevlar, fibreglass, etc.), it will not spall if a penetrator does make it through.
There is also this source that say that another metal layer can adequately catch any residual spalling.:
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They cited Hunnicutt when saying this about the M1 Abrams.:
Low rate initial production (LRIP) of the vehicle was approved on 7 May 1979.[
That document states that Chrysler built 110 more XM1s for more testing until the vehicles became the standardized M1s in 1981. If you look at production dates for the M1 Abrams from different sources, they say M1 production started in 1979 or 1980. Where do we draw the difference between them? The XM1 became the M1, and therefore is an Abrams.
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Well, depends what the last metal layer is, if its soft steel 1mm thick, thats not gonna make much spall. It just means whatever the last layer is, that will spall. It just means you want to make the last layer have negligable amount of spall.
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I’m a bit curious on this one because they cite it’d add 4800lb of weight, but the CATTB only has its spall-liner add… 1,250 pounds.
No. He just knows what hes talking about. The 2nd link literally says spall liner and shows a hard backer
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I mean, even Ironclads use a hard backer for their armor layout.
It was called wood. It was the backer and the spall liner for those ships
Revolutionary technology from 1859
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If its aluminum or titanium and its thin itll probably not spall at all, or just very minorly
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Depends a lot on the alloy and its hardness a shattering characteristics.
I do suspect modern hard backing has very negligable spall.
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Wonderful example here
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Especially if it’s adhered to a decent spall liner. This one really upsets them.:
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“GLASS NOT METAL!!! HOW YOU SAY IS SPALL LINER??!!”
That’s pretty much been their entire schtick. Then when I even show them studies and reports demonstrating metal layers with spall liners in between, they get mad and say a spall liner has to be what they want it to be and can’t possibly be integrated in any other fashion.
They are truly delusional.
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exocett is a cheater defender lol
This isn’t the Leo thread no matter how many threads they want to derail.
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Honestly I did a fair bit of digging back when the liners were first announced and I have my concerns.
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There’s this from 1977 when it had a 40mm grenade launcher
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A 78 hearing on upgunning the XM1 from 105 to 120
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Another '78 meeting involving the 120 and related turret modifications
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A '79 document noted compartmentalization to increase odds of the crew surviving a hit
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A meeting from 1980 where a general was very wary about more weight increases
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My concerns are limited production runs started in '79, mentions about the spall liners started to dry up with the only specific mentions being spall liners for any ammo put in the turret and whatever that spall box in the image is.
They mention compartmentalization, not spall liners to enable crew to survive penetrating hits, a spot I’d expect it to be brought up, they really didn’t want to add any weight to it, the pentagon really did not have a repeat of the MBT-70 and its costs and the constant committee meetings with politicians had them constantly questioning both the time it was taking to enter service and the money being spent.
Liners at this time period really weren’t some secret either, they talked openly about them being tested and implemented in the M113 and Bradley.
So there’s a not zero chance for one reason or another it was dropped, history is littered with military projects that got downgraded on the path from the drawing board to prototypes to production.
That study in the OP is sponsored and paid for by the US goverment so I’d expect gaijin will take it as a primary source and my worry is they’ll take that, combine it with the real lack of info and offer some other pittance of a buff instead.
They seem to want very specific details not only about the liners existing but also where exactly they are situated in the tank and without that we are screwed even if the liners did exist.
So in short, the addition of liners are stupid, the original addition of liners to a single tank is stupider, not researching in advance and implementing it to all tanks at once giving certain vehicles advantages is stupid and this whole thing is a debacle that should have been avoided.
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Good finds. Though even some of these documents references aluminum walls being used as spall liners. There’s nothing saying spall mitigation is not incorporated into the composite armor layers. But with them being classified, we can’t prove that’s how it’s done.
Just because they removed the spall box/storage boxes with spall panels from the turret does not mean there aren’t spall liners anywhere in the design.
This document hammers on the point that crew survivability was the number one priority of the XM1 program.:
'With the Soviet threat in mind, Congress authorized a new effort to develop a main battle
tank at the same time it canceled the XM803 program (see timeline of Abrams
development at the end of the chapter). The Army set up a task force at the Armor School
at Fort Knox, KY. With help from the Advanced Concepts Branch at Tank-Automotive
Command (TACOM), the task force identified 19 characteristics that a new tank should
possess. It listed them in order of importance, the first five being:16
• crew survivability;
• surveillance and target acquisition performance;
• high probability of hit with first round
• time to acquire and hit a target;
• cross-country mobility. ’
‘Crew Protection
The initial XM1 study team at Fort Knox named crew survivability as the number one
priority for the new main battle tank. A great many of the technological advances on the
Abrams discussed elsewhere in this report contribute to crew protection—greater speed
and agility for less exposure to enemy fire, a lower noise signature, and better armor, to
name a few.’
Considering that we also have multiple primary source documents that mention the XM1 design that was standardized as the M1 in 1981 had spall liners, I think its safe to say the document that wasn’t even produced by the Army, and had no insight or involvement in the Abrams development, is less than conclusive on the Abrams protection design.
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