ATAC and the Armor/Anti-Armor Program

18 Pages·1999·1.71 MB·English

Armor/Anti-Armor
The Rand Corporation, E. I DuPont de Nemours, Honeywell, Inc., Battelle Washington Operation, Textron Defense Systems
A
chief concern driving the cur- tors and electronics), materials proper- challenge industry in the key technolo-
rent U.S. armor/anti-armor ties (especially at high strain rates and gies by making the research, develop-
program is that the Soviets extreme pressures), and computer mod- ment, test, and evaluation stages of the
have a significant lead over eling. Further, the precision required for national program highly competitive.
the United States in tanks and antitank nuclear ordnance has forced the Labo- The strategy has been implemented
weapons (see “A Comment by General ratory to explore these technologies at by breaking the core of the Armor/Anti-
Starry”). Moreover, simple solutions in very detailed and precise levels. Armor Program into three major ele-
armor and anti-armor technology have Throughout the 1970s Los Alamos ments: the Blue Teams, the Red Design
already been implemented, so it may contributed to Department of Defense Bureau, and ATAC. The Blue Teams
no longer be possible to find a “quick conventional munitions. For example, consist of contractors who are develop-
fix” that will catapult the conventional we developed a uranium alloy to serve ing armor and antitank weapons. These
U.S. forces to a decisive lead over the as an armor-piercing round for the Air contractors are large industrial corpo-
Soviets. The problems are complex and Force. The material proved so effective rations that have enlisted universities,
the science sophisticated enough that it became a standard for large-caliber national laboratories, and other corpo-
we cannot depend on small, incremental Penetrators. We also collaborated with rations as subcontractors to help with
improvements. We must base new solu- industry and Navy laboratories to solve their competitive efforts. The first phase
tions on a better scientific understanding a propellant safety problem that threat- of the program involves about 130 ma-
of materials and their behavior under ened the Trident system. This last effort jor contractors selected from an original
ballistic conditions. led to the joint development—by Los field of over 400 companies.
As a result the national Armor/Anti- Alamos, Lawrence Livermore National The Red Design Bureau—headed by
Armor Program, although spearheaded Laboratory, and the Air Force Rocket Battelle Memorial Institute in Colum-
by DARPA (Defense Advanced Re- Propulsion Laboratory-of a method- bus, Ohio was created to design a “So-
search Projects Agency), is also a col- ology for testing the safety of solid viet threat” for the competitive stages of
laborative effort with the U.S. Army, rocket propellant. One of our most no- the program. The threat is based on an
the U.S. Marine Corps, and 130 corpo- table contributions was the long standoff independent evaluation of available in-
rations, laboratories, and universities. penetrator, a shaped-charge, chemical- telligence data. In other words, the Bu-
A key element in this collaboration is energy weapon that was tested in 1979 reau tries to “think Soviet, ” design what
the Advanced Technology Assessment and shown to penetrate more deeply into the Soviets might be designing, and then
Center created at Los Alamos to pro- armor than any other such weapon. In- fabricate actual prototypes. These futur-
vide the strong scientific base needed terest in the design of this penetrator istic Soviet armors and Penetrators are
for high-tech advances in armor and ar- led to more extensive Los Alamos in- used to test and assess the Blue Team
mor Penetrators. ATAC serves as both a teractions with Department of Defense hardware. Members of the Blue Teams
testing center for new developments and munitions researchers and, ultimately, to do not learn what the threat will be until
a scientific resource that all participants the choice of Los Alamos as ATAC. about a month before competitive test-
can draw upon. ing.
A major impetus for choosing Los The roles of ATAC are, first, to stim-
Armor/Anti-Armor
Alamos as the Advanced Technology ulate the entire process by transferring
Program Goals
Assessment Center was history: there technology from Los Alamos to indus-
has always been a synergistic and inti- The long-term goals of the national try and, second, for the Laboratory to
mate relationship between the Labora- Armor/Anti-Armor Program are to de- serve as a neutral referee in the compet-
tory’s nuclear and conventional weapons velop a broad base of expertise in pri- itive stages. Specifically, ATAC helps
technologies. In the early days of the vate industry and make that expertise the Blue Team members develop better
Manhattan Project, ordnance experts available to the U.S. Armed Forces. On products, and then it tests those products
came to Los Alamos to design essential a short-term basis the national program against the threat created by the Red
components of the first nuclear devices. also hopes to increase the rate at which Design Bureau. Much of the help pro-
The overlap between the design of nu- we modernize armor and anti-armor vided by ATAC comes from two major
clear and conventional weapons that was systems until the U.S. can outperform areas of Los Alamos research: mater-
established then, and which continues the Soviet Union in the development of ials science (see “Armor/Anti-Armor—
today, includes the hydrodynamics of several key technologies. The strategy Materials by Design”) and computa-
high explosives, firing systems (detona- devised to accomplish both goals is to tional codes (see “Modeling Armor Pen-
Los Alamos Science Summer 1989
Armor/Anti-Armor
General Research Corporation, Nuclear Metals, Inc., Aerojet Ordnance Co., AAI Corporation, FMC Corporation, Physics International Company
etration”). ATAC is also responsible however, they appeared much more ef- microstructure of the liner are critically
for ensuring that testing of Blue Team ficient than expected. In truth, no one important. Additionally, we have found
products is performed and evaluated ac- understood how the armor worked. that a specific “heat and beat” fabrica-
curately, thoroughly, and without bias. Eventually it was proposed that the tion process for each material has to
Our evaluations include recommenda- breakup created a mass of hard, abrasive be followed to achieve the preferred
tions for future funding of promising ceramic chips that eroded the penetrator. crystalline microstructure. We had to
technologies. Detailed computational and materials explore a variety of these processes
ATAC’S effectiveness in the Armor/ research at both Los Alamos and Liv- to select the correct one—an expen-
Anti-Armor Program requires that Los ermore confirmed this hypothesis and sive, time-consuming task if done solely
Alamos be at the technical forefront of made us realize how to turn the appar- on an experimental basis. We hope to
armor and anti-armor research. Thus ent disadvantage to our favor. The goal shorten the task considerably by us-
ATAC invests a significant portion of was then to keep fractured ceramic in ing a computer model to predict liner
its budget in research on materials sci- front of the penetrator as long as possi- performance based upon various crys-
ence and technology, development of ble, causing the rod to erode as it forced talline microstructure. We will make
diagnostic techniques, and computa- its way through the rubble. As a result, this information and the modeling code
tional research. In addition, Los Alamos how the material was packaged became available to others, including Blue Team
has contracted a number of consultants as important as its strength and fracture contractors. In fact, industry has been
and universities for help in disciplines characteristics. briefed on the preliminary work.
outside the expertise of Los Alamos sci- Only by examining defeat mecha- We are hoping that the same process
entists. nisms in this detailed way can scientists evolves for kinetic-energy Penetrators,
optimize both the material character- which several Blue Team contractors
istics (abrasive chips) and product de- have undertaken to explore. At present,
A Scientific Challenge
sign (how to confine those chips) to the idea that dominates development of
The basic challenge in armor/anti- enhance the desired effects. (See both kinetic-energy Penetrators is simply that
armor research and development is to “Armor/Anti-Armor-Materials by De- the heavier the penetrator and the faster
understand each problem from sound sign” and “Studying Ceramic Armor it hits the target, the better. However,
physical principles and the appropriate with PHERMEX” for a fuller discussion Blue Team contractors are asking them-
materials properties. For example, our of ceramic armors.) selves several questions: What mechan-
thinking about the usefulness of ceram- The same challenge of’ understanding ical properties should be considered?
ics as armor material changed drastically the physics of the ballistic event, the Does fracture toughness give the pene-
with an increase in our understanding materials involved, and the effect of trator its ultimate strength? What effect
of ceramic material properties and how product design is true for Penetrators. does chemical composition have on this
ceramics react physically to ballistic im- An example is the metal liner used in strength? In other words, a better under-
pact. chemical-energy weapons. The detona- standing of the physics of high-velocity
One of the most efficient ways for tion of a shaped charge moves this liner impact needs to be acquired. This is the
armor to defeat a projectile is to turn at the target in such a way that the ma- type of challenge facing the Blue Team.
most of the kinetic energy back into de- terial transforms into a high-velocity jet
struction of the projectile itself, say by of solid stretching material. To be ef-
Current Research
fracture or plastic flow in the penetra- fective, the liner must have the proper
tor. Ceramics were considered possible combination of strength and ductility to Further advances in the develop-
as armor material because they gen- allow it to stretch without breaking. ment of the chemical-energy warhead
erally have high compressive strength If one is to achieve a desired liner is a tactically urgent problem that the
and are lightweight, two qualities de- performance, criteria—such as the ma- Armor/Anti-Armor Program is currently
sirable for mobile weapons systems terial density, the tip velocity, and the tackling with much vigor. Before re-
that need tough, light armor. Unfortu- coherency of the jet—must first be de- active and spaced armors were intro-
nately, ceramics also tend to be brittle termined. Then the key elements neces- duced, chemical-energy weapons had a
and break up easily on impact, which, it sary to those criteria must be identified. number of clear-cut advantages. For in-
was thought, would undermine the ma- For instance, work at Los Alamos has stance, the chemical-energy penetrator
terial’s ability to destroy the penetrator. shown that selection of liner material, is better at penetrating steel armor than
When ceramic materials were tested, design of the charge, and the crystalline continued on page 56
53
I.os Alamos Science Summer 1989
w
A e are behind the Soviets to catch up and frequently as long as fif-
in both armor and bullets. teen years to apply the same technology
That simple declarative in our fielded systems.
Comment sentence is what makes the ratification “This is not an indictment of our in-
of the Intermediate-range Nuclear Force telligence system. We do gather suf-
(INF) treaty a provocative action. It is ficient information on which to make
bv the raison d’etre for the new national in- fairly reliable estimates. In fact, three
terest in armor and anti-armor technolo- years ago we had the intelligence com-
gies. And it was the principal finding of munity make some estimates of what
General the 1985 Defense Science Board Task was in the ‘bathtub;’ to no one’s sur-
Force on Armor/Anti-Armor, of which I prise, those developments are now be-
was the chairman. ginning to appear.
Starry “Our Task Force study reported that, “The flaw, instead, is in our decision-
in armor and anti-armor systems, the making process. Our system reacts
U.S. has been behind the Soviets for positively only when confronted with
perhaps fifteen to twenty years, and we hard evidence—a photograph of fielded
are falling further behind at an alarm- equipment—and negatively to an in-
ing rate (see Figure). Back in 1985, telligence community ‘bathtub’ projec-
we considered the problem as one ‘ap- tion. No one in Washington is willing
proaching a matter of national urgency.’ to make a decision until shown a picture
Today we have crossed the threshold; of a fielded system incorporating new
the situation is now a matter for urgent technology; then there will be all sorts
national priority. of doomsday and ‘how could this have
“The problem is not a lack of tech- happened’ reactions.
nology or intelligence data. Scientific “So the first problem our country has
journals and other open literature collec- is how we look at the threat. The sec-
tively provide a fairly substantial body ond problem is one of technology field-
of data from which we can determine, at ing. We are fighting against a natural
least by inference, what they are doing tendency of laboratory scientists-even
in research and development. at places like Los Alamos—to keep the
“However, over time, we find infor- technology at the workbench too long.
mation concerning a given technology Of course, they want to keep improv-
declining in volume or even disappear- ing the capabilities, But if you allow
ing from their literature, Does this mean the scientists more and more time and
that the Soviets have given up on a funds, you may end up with a wait of
technology? The U.S. has a tendency five to ten years, an expenditure of mil-
to believe so. That may be true, but it lions or billions of dollars, and only a
is equally possible that they have moved marginal improvement in performance,
the technology into full-scale engineer- In other words, a laboratory has no in-
ing development. Eight to ten years centive to get the technology out.
may pass. Then, all too frequently, “It is vital to have a decision-making
we identify what we would call a new mechanism to drive the technology off
weapon system on a test track or, in the workbench and into the field. The
some cases, being issued to the troops— Soviets have such a mechanism: the
a system that fields the so-called disap- five-year planning process. Relentlessly,
peared technology. every five years the Soviets transfer
“The Task Force called this decline of technology from the bench to the field.
information during full-scale engineer- We have-no similar system. In fact, the
ing the Bathtub of Ignorance, Histori- Task Force examined thirty of our tech-
cally, it has taken us at least five years nology developments and found at least
Armor/Anti-Armor
60
SOVIET AND U.S. TANK DEVELOPMENT
50
40
of Tanks
(thousands
30
20
10
0
Year 1948 1958 1968 1978 1988
* Classified or unknown
U.S./SOVIET T-55 T-62 T-64 T-72 M-1 T-80 FST-I
Crew 4 5.,,,,.,,,,.,,,4,,,,,,,,,4,,,,,, 4 4 3 3 4 3 l
*
Combat Weight 35 41 57 42
(metric ton)
Power/Weight Ratio 14.4 17.5 18.0 14.2 184 higher . *
(horsepower/rnetric ton)
*
Maximum Road Speed 48’ 48 42 48 50 50 80 60 66 90
(kilometer/hour)
Main Gun Diameter 100 90 90 105 100 115 125 125 105 125 *
(millimeter)
Turret Front Armor , *
203 115 203 242 * 280
Thickness (millimeters)
Soviet tank development outpaces that of the U.S. both in total numbers and in the introduction of modern technology. The Soviets regard
the tank as the primary element of their ground combat power, and Soviet military theory emphaslzes the Importance of the tank in the
combined-arms team. As a result, the Soviets commit a major portion of their resources to their tank industry, achieving an Integrated,
evolutionary program of tank development that produces thousands of main battle tanks each year. Long-term improvement can be seen
In all three Soviet armor subsystems-firepower, protection, and mobility. Modern tanks (T-64, T-72, and 1-60) now make up approximately
forty per cent of the Soviet force in the field. (The information for this figure was compiled by the International Technology Division of the
Los Alamos National Laboratory.)
Los Alamos Science Summer 1989

Armor/Anti-Armor
Aluminum Company of America (ALCOA), General Motors Delco Systems Operation, A.R.A.P. Division of California Research and Technology
But the situation started to reverse people in the weapons community fear portant. To improve fracture toughness
itself in the mid-to-late 1970s when that fielded chemical-energy warheads without sacrificing the other properties,
the advent of spaced armor, then ce- are now obsolete. However, prelimi- we are investigating the use of single-
ramic laminate armor, and finally re- nary tests of some new chemical-energy crystal whiskers or platelets as a rein-
active armor reduced the effectiveness warheads developed by Blue Team con- forcement in ceramics. Tailoring mate-
of chemical-energy weapons. Today tractors show promising results. Signifi- rial properties for specific applications is
the combination of spaced or ceramic cant improvements in performance seem one of the challenges of armor develop-
armor and reactive appliques has prob- attainable with existing technology. Un- ment.
ably made every fielded system using a fortunately, we cannot give more details
chemical-energy warhead obsolete. on these developments due to the pro-
Interface With Industry
Reactive armor-used first by the Is- prietary nature of the new designs.
raelis in the 1970s and now estimated We can, however, talk about one How is Los Alamos helping industry
to be on half of the Soviet tanks—is a promising concept—tandem chemi- to meet the challenges of the Armor/An-
formidable challenge (Fig. 2). It was cal-energy warheads (Fig. 3). In these ti-Armor Program’? A recent incident
developed primarily as a countermea- weapons a small charge at the front of illustrates how ATAC’s presence at Los
sure for chemical-energy weapons and the warhead fires to activate the tank’s Alamos allows the program to tap the
consists of a trilayered sandwich of reactive armor. A time delay allows the Laboratory’s experience and developed
metal, high explosive, and metal. Tile- reactive-armor plates to move out of the technology. Los Alamos has always
like boxes of reactive armor are simply way, then a large shaped charge further performed nondestructive inspections
bolted to vulnerable areas of a tank out- back in the warhead fires a metal jet to of every nuclear weapon system tested.
side its existing armored shell. defeat the base armor. Weight reduction It was thus only natural to perform the
Because of the ability of reactive ar- technologies, various time delays be- same tests on the chemical-energy war-
mor to destroy an incoming jet, some tween the firing of the two charges, and heads sent to us by Blue Team contrac-
innovative designs and materials for the tors. The evaluations revealed hereto-
shaped-charge liners are currently being fore undetected cracks and voids in
developed. Blast shields between the some of the warheads that could have
precursor and the main charge are being affected performance. We informed
optimized, and the most effective stand- the contractors of the problems so they
off distance- the distance to the shaped could make substitutions, thus ensuring
charge at the instant of its detonation— that all participants had a fair chance in
is being determined. Tandem chemical- the competition.
energy warheads seem likely to play an ATAC also provides direct help in
important role in the defeat of reactive solving contractor’s problems. Our
armor. program managers, test directors, hy -
The national Armor/Anti-Armor Pro- drocode developers, and materials sci-
gram has also taken up the challenges of entists deal on a one-to-one basis with
new composite materials and advanced our industrial counterparts. For exam-
processing techniques. To achieve the ple, last summer we worked with the
REACTIVE ARMOR
low weight and elevated mechanical company that produces the Joint Ser-
Fig. 2. Reactive armor typically has a layer of properties needed for armors, the ideal vices hypervelocity missile to help solve
high explosive sandwiched between two lay- material may actually be a composite a control problem. The missile con-
ers of armor plate. When a high-energy jet col- of ceramic and high-strength reinforce- sists of a large kinetic-energy penetra-
lides with the armor, the explosive detonates, ments. Ceramics possess low density, tor mounted in the missile’s warhead.
pushing the plates into the path of the jet to high hardness, dilatancy (the tendency Although the warhead is very heavy,
deflect or deform it, thereby protecting the in- to expand when fractured), and high the missile is long range and able to
ner layer of armor. Ideally, the reactive armor shear strength—all good properties for move fast— 1.7 kilometers per second.
plate will be moving at an angle to the path of armor-but they lack fracture tough- Unfortunately, the aluminum tins on
the jet, forcing it to drill a slot rather than a ness, the ability to resist crack propa- the missile-critical to its stability and
hole through the plate and giving the plate a gation, which for some purposes, such control-melted during flight. We even-
larger effective thickness. as multiple-hit resistance, may be im- tually solved the problem by suggesting
57
Los Alamos Science Summer 1989
A TANDEM WARHEAD
Fig. 3. One concept for defeating reactive ar-
mor is to use a chemical-energy warhead with
two explosive charges rather than one. As the
warhead approaches the armor (1 through 3)
the small explosive charge at the front of the
warhead is detonated. The resulting impact
activates the explosive in the reactive armor (4
through 6), causing the plates of armor to be
blown away. Later, the large explosive charge
at the rear of the warhead fires (7). However,
the angle of the armor and the gap between
the warhead’s initial and final charges causes
the plates to miss the penetrating jet formed
by the detonation of this second charge.
Armor/Anti-Armor
California Research & Technology, Kaman Sciences, Inc., Lawrence Livermore National Laboratory, Radkowski Associates, General Dynamics
both a particular ceramic coating and an
ROCKET SLED
application technique for the coating.
Fig. 4. A chemical-energy warhead is shown being tested on the rocket sled at Los Alamos.
Mounted on a 1000-foot monorail, the sled can reach Mach-1 speeds and allows scientists to test
ATAC Facilities
warheads under controlled but realistic conditions.
ATAC, in its role of testing and eval-
uating the competing antitank systems
and armors, uses Laboratory expertise,
technologies, and capabilities. For ex-
ample, we are testing chemical-energy
warheads using the 1000-foot monorail
rocket sled track at Los Alamos (Fig. 4).
The sled can reach Mach-1 speeds, and
the track can be extended to 2000 feet
if higher speeds become necessary. The
sled track is very useful for carrying
out realistic tests of tandem-warhead FLASH X-RAY MACHINE
designs. Most tandem designs have a
significant time delay between firing the Fig. 5. A flash x-ray machine being constructed at Los Alamos capable of “viewing” ballistic
first and second warheads, during which events through eight inches of steel. When the 8 to 10 million electron volts of energy stored in
time the second warhead moves consid- the Marx generator are released into the diode envelope, electrons accelerated from the cathode
erably. The rocket sled can be used to to the anode will generate an x-ray fluence greater than 500 roentgens 1 meter from the end of
test the effect of missile motion under
precisely controlled conditions.
We are also building a new intense
flash x-ray machine next to the sled
track, This machine should allow ar-
mor and anti-armor developers to “see”
the penetration process through eight
inches of steel (Fig. 5). The source
in this system will operate at 8 to 10
mega-electron-volts (MeV) and generate
an x-ray dose greater than 500 roent-
gens at 1 meter. This device will easily
track both kinetic-energy Penetrators
and chemical-energy jets well inside the logged and processed automatically by ATAC built the range at TERA because
targets. computers, which allows Los Alamos sufficient land was not available at Los
Los Alamos also designed and helped personnel to control the firing times Alamos for safe firing of full-size live
develop a state-of-the-art test range in of munitions and to measure time and miss iles and projectiles.
Socorro, New Mexico, at the Terminal space information relative to the arrival A variety of other diagnostic ca-
Effects Research and Analysis (TERA) of the devices. Technical calculations pabilities are available for gathering
branch of the New Mexico Institute can be done directly from the video. the maximum data from each test per-
of Mining and Technology. The range There is also a four-camera. single- formed at Los Alamos, These include
occupies 1 square mile and features a image system with a ten-nanosecond four portable 2-MeV x-ray systems,
highly instrumented target area that fol- shutter speed. The multiple cameras, twelve 450-keV flash x-ray machines.
lows the incoming trajectory and target combined with electronic imaging, per- five rotating-mirror streak cameras with
response optically. A continuous record mit Los Alamos personnel to locate the writing speeds of 20 millimeters per mi-
of the test is provided by an advanced position of munitions within the target crosecond. four image-intensifier cam-
video system that operates at speeds up area and not interfere with the muni- eras with X)-nanosecond shutter times,
to 2000 frames per second. All data are tions control and guidance equipment. a laser velocitmeter and a microwave
Los Alamos Science Summer 1989 59
Armor/Anti-Armor
General Electric Company, Ordnance Systems Division, Science & Technology Associates, New Mexico Institute of Mining & Technology
Fig. 6. One of the goals of the national Armor/Anti-Armor program is to establish a useful flow of
information between the military, industry, and various research institutions. The interactions of
ATAC with this network continue beyond the research phase into the testing, development, and
perhaps even production phases of the weapon systems.
Richard Mah is the director of ATAC and a formcr
group leader in the Materials Science Division al
Los Alamos. Prior to coming to the Laboratory, he
worked as a senior research engineer at Dow Chem-
ical and C. F. Braun & Co. Hc holds dcgrccs in
theoretical and applied mechanics and metallurgical
cngineering from the Universiy of Illinois and has
published over twenty papers on materials science
velocimeter to record transit velocities, Armor-Materials by Design”). When topics.
time-interval meters with nanosecond the military told the Laboratory about
resolution, 200-megahertz analog-to- the need for a less expensive ceramic
digital signal converters, and a wide armor, our materials scientists tested
range of more conventional instrumen- various ideas and developed a process
tation, We also can use PHERMEX, for fabricating a less expensive but
a 30-MeV flash x-ray machine, and equally effective ceramic armor. We
ECTOR, a 3-MeV machine. Both of then initiated transfer of the technolog-
the machines have access to impressive ical concepts to industry, and Allied
digital-enhancement capabilities for flash Signal used the ideas to develop their
radiographs, and they allow us to deter- own armor package. Allied Signal is
mine the internal structure of anti-armor now busy producing prototypes of the
and armor devices at the time of impact armor, which they will submit for test-
(see “Studying Ceramic Armor with ing and evaluation at ATAC. If that ar-
PHERMEX”), mor is successful in the competition, it
will eventually become a new product
available for military use.
An Evolving Process
The true value of the national Armor/
At ATAC we can see a new process Anti-Armor Program may not lie in a Phyllis Martell is the technical writer and public re-
evolving among industry. the military, simple leapfrogging of Soviet armor and lations manager for ATAC at Los .Alamos and pub-
lishcs a newsletter, The BULLET, on Armor/Anti-
and the Laboratory in which a natural bullets by U.S. technology. Rather it
Armor Program activities. Before joining the Lab-
interplay of needs, research, testing, pro- may lie in the way this uniquely struc-
oralory, she was the public information officer for
totyping, evaluating, developing, and tured program has opened fresh inter- the Los Alamos School District. She holds a de-
procuring guides the development of actions between our nation’s military, gree in French and English from the University of
armor and anti-armor systems (Fig. 6). industries, laboratories. and universities Wisconsin.
To illustrate how the process works, that will allow us to constantly maintain
consider the case of ceramic-filled poly- an edge over the Soviets. n
mer armor (described in “Armor/Anti-
60 Los Alamos Science Summer 1989