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UNCLASSIFIED AD295 739 ARMED SERVICES TECHNICAL INFORMATION AGENCY ARLINGTON HALL STATION ARLINGTON 12, VIRGINIA UNCLASSIFIED

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Page 1: AD295 739 - DTICfor 'bulls-eye' capability is particularly emphasited. The design of equipment for measurement of center of gravity location for warheads has been left to the various

UNCLASSIFIED

AD295 739

ARMED SERVICES TECHNICAL INFORMATION AGENCYARLINGTON HALL STATIONARLINGTON 12, VIRGINIA

UNCLASSIFIED

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NOTICE: When government or other drawings, speci-fications or other data are used for any purposeother than in connection with a definitely relatedgovernment procurement operation, the U. S.Government thereby incurs no responsibility, nor anyobligation whatsoever; and the fact that the Govern-ment may have formulated, furnished, or in any waysupplied the said drawings, specifications, or otherdata is not to be regarded by implication or other-wise as in any manner licensing the holder or anyother person or corporation, or conveying any rightsor permission to manufacture, use or sell anypatented invention that may in any way be relatedthereto.

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(3

C,)

PICATINNY ARSENAL-

.m~rmmm...1TECHNICAL REPORT 3059

A UNIQUE UNIVERSAL TYPE INSTRUMENTTO

I LOCATE CENTER OF GRAVITYOF

VARIOUS WARHEADS A ST IA

DAVID STEIN EB816MARK H. WEINBERG FEB 8_19

AMCMS 4120.28.3033.12 JiZMA

COPY NO. 31DECEMBER 1962

PICATINNY ARSENAL* DOVER. NEW JERSEY

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ASTIA AVAILABILITY NOTICE

Qualified requesters may obtain copies of this report

from ASTIA.

The findings in this report are not to be construed as

an official Department of the Army position.

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Picatinny Arsenal Technical Report 3059

A

UNIQUE TYPE INSTRUMENT

to

LOCATE CENTER OF GRAVITY

of

VARIOUS WARHEAM

byDavid Stein

Mark H. Weinberg

AMCMS 4120.28.3033.12 December 1962

REVIEWED BY: APPROVED-Y_

W. F. McClure Robert E. Todd

Acting Chief, Test Chief, Ammunition

Methods & Equipment Inspection Engineering

Section Branch

QUALITY ASSURANCE DIVISIONPICATINNY ARSENALDOVER, NEW JERSEY

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ACKNOIDGEDTS

TO:

Mr. Edward F. Bauer, Test Methods and Equipment Section, imeunition

Inspection Engineering Branch, Quality Assurance Division, for his

contributions of ingenuity, practical suggestions, and general assistance

throughout this program.

Mr. Joseph V. Rusby, Gage Calibration Laboratory, Inspection

Operations Branch, Quality Assurance Division, who gave valuable assistance

in the metrology and inspection of this instrument both during and after

its manufacture.

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V TAB OF CONTUTS

Page

Abstract 1

Conclusions and Recommendations 2

Symbols, Definitions and Conventions

Introduction 6

Description of Instrument 8

I. Theory of Operating Principles .8

A. Longitudinal CO 8

B. Radial OD i1

II. Design Features

A. Fulcrum 12

B. Balancing Moments 16

C. Levels 16

D. Adjustability Features 17

S. *Universal' Standard 18

F. Handling 20

MII. Outline of Procedures 22

Index to Photographs 23

Index to Appendices 31

Distribution List (Following Appendix F)

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ABSTRACT

A unique, universal type device to locate the center of gravity of

various warheads is described. Simple basic principles are utillzed in

a new configuration to produce a highly precise instrument which may be

adapted to locate center of gravity of warheads with a constant accuracy

of about 0.002 inch. Both longitudinal distance from warhead reference

surface and radial displacement from warhead axis are determined in a

single handling of the warhead, thereby eliminating the need for two

separate devices.

The instrument was designed specifically for warheads in the Little-

john and Honest John Systems (weight range up to 1700 pounds; centroid up

to 37 inches from rear mounting surface). However, its total range of

capability extends from essentially zero to a warhead which exerts 80,000

inch-pounds of moment (warhead weight times centroidal distance from

rear reference plane).

Mounting provisions are made for the following items of current

production: Littlejohn Warheads M146 and M5, and Honest John Warheads

M38, M132, and M144.

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COCLUSIONS AND RECCOWDATIONS

Evaluation of this instrument through performance of a series of

calibrating and use tests have proved that its capabilities exceed

initial design objectives by a factor of five in accuracy. All values

required to be determined are readily measurable through use of the

instrument.

The basic principle of the design, suspension of the total mass

from a single pivot point, is shown to be a highly effective method of

attaining the desired results. It is felt that the overall design,

with its great flexibility, utility and accuracy, represents a signi-

ficant advance to the state of the art. Its representation in the

presently existing prototype is a highly useful device.

The authors recommend consideration of extension of the experience

gained here to design of more sophisticated instruments. For example,

one could visualize an instrument which would have balancing weights

whose positions are controlled by a servo system, with automatic readout

of net moment required to reach balance. An instrument could be readily

designed to be self-balancing, with the pivot being adjustable to the

extent that the completely unloaded instrument could be leveled, thus

eliminating the need for any standard such as is required for the exist-

ing prototype instrument. A further possibility would eliminate any

balancing weights, accomplishing balance by means of a movable pivot

whose position longitudinally and radially would establish the warhead

center of gravity position.

Determination of the weight of the warhead is beyond the function

of the present instrument, and thus subject to unknown variations.

Incorporation of a load cell inLo the fulcrum support would make the

instrument fully self-contained and independent of external weighing

means, and would assure weight (and thus center of gravity location)

determination within known uncertainty limits. Then the operating

instructions and acceptance limits can take this known uncertainty

into account to assure acceptance of only good units.

Based on the experience gained from construction and testing of

the prototype instrument, a redesign effort is currently in process.

This will provide:

2

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1. Simplified construction details in the areas of vernier

adjustments and side-sway control.

2. Reduced weight and elimination of all end-play in the bearing

assembly.3. Built-in facilities for checking and setting true vertical

alignment, and4. The integral weight measuring load cell noted above.

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SYMOWM, WFINITTNS AND CON VDTIQ4S1. Symbols

k - Distance from pivot axis to face plate, measured along x-axis

M - Total longitudinal restoring moment

M1 - Front balancing moment = WIs

N2 - Rear balancing moment = W2,1N - Radial restoring momentXv - Moment exerted by I pound vernier weight at rear of instrument,

equal in inch-pounds to pointer reading on scale.

R - Radial displacement of warhead C0 from warhead axis

aI - Distance from pivot to front balancing weight COa2 - Distance from pivot to rear balancing weight 00

W - Weight of warhead

W1 - Balancing weight added to front

W2 - Balancing weight added to rear

WA - Weight of special adaptcn- to w.ouxt particular warheadWF - Net fixture weight (does not include weight of pivot cage)

- Longitudinal location of warhead center of gravity, reasured fromdesign refarence pcint on warhead

A "Longitudinal location of special adapter center of gravity, measuredfrom faceplate mounting surface

XF - Longitudinal location of fixture center of gravity, measured fromfaceplate mounting surface

- Distance from CG of standard to mounting surface of padsWs - Weight of standard

2. Definitions

Accuracy - A bias in the average of a set of readings from a standard.Balancing Moment - Restoring noment.

Center of Rotation - When a warhead 4s mounted on the instrument androtated in order to detertne 4.he radial lccation of the CG, theCO will dascribe a cirl-3 atout the axis of rotation. (NOT!: Theinstrument faceplate ard adaptor plate are designed to cause thecenter of rotation to all n the warhead axis.)

4

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Precision - A measure of repeatability.

Restoring Moment - The moment required to re-establish a level

balanced condition.

Sensitivity - The minimum moment required to produce a measurable

imbalance per unit weight of warhead.

Warhead Axis - The line passing through the center of, and perpendicu-

lar to the plane of, the datum circle of the warhead. (On

Littlejohn, this is on a tapered surface which is a portion

of a right circular cone; on Honest John, it is a bolt circle.)

3. Conventions

Restoring radial moments are taken as positive when clockwise, viewed

from rear.

The rear of the instrument is the end at which the levels are located.

5S

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INTROWCTIOS

Weight and center of gravity (cG) location are but two of many

parameters which must be considered in the design of an amnunition item

which, at some time during its brief functional life span, must conform

to a desired trajectory, or path. With the advent of intercontinental

ballistic missiles and their offspring, anti-nissile missiles, the need

for 'bulls-eye' capability is particularly emphasited.

The design of equipment for measurement of center of gravity location

for warheads has been left to the various contractors. It is not sur=

prising, therefore, to learn that there exist as many different designs

of C equipment as there are contractors. The review of these designs

and evaluation of the equipment performance has been, and continues to

be, a major area of interest and aotivity of inspection engineering per-

sonnel of the Quality Assurance Division of Picatinny Arsenal.

Needless to say, considerable background has been obtained from this

activity. Thus, in the design of the equipment described in this report,

many of the desirable design features provides by otter designers have

been borrowed. However, in no case does there appear to be contractor

data of tests to describe equipment performance to the extent reported

herein. This is not said in condemnation; it murt be recognized that the

contractor is guided by considerations of time and economy. His CG equip-

ment 4s, after all, but one or two of many measuring devices he mist employ

to sell hJs end item, That his CO equipment provides valid results has

been the principal objective in the review of his design and his equip-ment, This can be done without the degree of t*sting reported here.

The Universal C device described in these pages was designed on the

basis of the following criteria desired to be lherert in its capabilities:

a. Measure longitudinal and radial CG location by variables

(rather than by attributes).

b. Measure skin concentric).:y (th .s Instrument does contain

this capability, and the incorpcration of this feature ir.fluenced the overall

design. In particular, the weight of the Instrument became heavier than

desired, but not to the extent tc Jeopardize its 0) masuring capabilities.

The remaianer of this report will cmrftne itself slely to OG oosidreticn).

6

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c. Handle warheads in the weight range of approximately 200 to

2,000 pounds, and in the (longitudinal) CO range up to approximately 40

inches from a (rear) mounting plane.

d. Be independent of the physical length of the warhead, provided

the warhead meets the requirements of paragraph c.e. Provide an accuracy of at least - 1/64 inch.

7

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DISCRIPTION OF DIST MT

The design of this instrument employs the 'restoring moment principle'.

The instrument and the warhead, when mated, becomes a single mass whose

resultant center of gravity seeks its neutral, or equilibrium, position

within the constraints imposed by the support. In this case, the support,

or fulcrum, is (theoretically) a single point which permits three degrees

of freedom: tilting in each of two perpendicular planes (Y-Z and X-Z)

whose intersection is the plumb line through the point of support (Z-Axis),

and rotation about this line. The latter motion is controlled and is not

used in the operation of the equipment. See Figure 1.

I. Theory of Operating Principles

A. Longitudinal 00

The basic instrument (see Photo 1) cannot balance by itself con-

veniently (or safely). In the photo, it is shown as being supported by

contact at the fulcrum point (hidden by the bracket on the A-frame, said

frame containing the cone supporting surface on the upper portion of the

horizontal member; see Photos 4 and 7) and contact with the retractable

Jack, which rests on the floor. If the Jack were to be lowered, the equip-

ment would follow the Jack downward because of the unbalanced moment,

until its center of gravity coincided with the plumb line through the point

of support. The situation is akin to an individual sitting on one end

of a see-saw, alone (Figure 2a).

By adding a warhead, the 'see-saw tends toward a balanced condi-

tion (Figure 2b).

The final balance is achieved by adding known weights at a known

(fixed) distance from the cone point, and the condition of balance (i.e.,

when the axis of the warhead is parallel to the ground) is evidenced by a

precision level (Figure 2c).

It is to be noted that if the fixture and the warhead had tilted

in the other direction, then weights would have been added at the front end

of the horizontal fixture beam.

From the foregoing, the calculation for the longitudinal OD of

the warhead (1), is seen to be nothing more than a simple lever problem

encountered in high school physics, or in statics. Figure 2c has been

8

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FRONT EAR

FULCRUM POINT

rIXTURE WEIGH4T

FIXTURE WEGHT

WARHEAD WE1864T

jA22Z!9* ADDED WCI"iPTS

FACEPLA-(Vam;abe D;Oanfce)

-(------

Fiu I

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embellished somewhat to show more of the quantities which must be consiaered.

For a complete analysis of the calculation for Y, the reader is referred

to Appendix A.

B. Radial O

In the following discussion, the axis of the warhead is assumed

to be collinear with the axis of rotation of the face plate. Furthermore,

it is assumed that this axis and the pivot point determine a vertical plane.

Three weights move in straight line paths perpendicular to this plane, ard

may be placed on either side of the plane, as required. Photo 5 shows the

three radial weights in the neutral (zero) position.

The largest weight (ten pounds) can be positioned in slots at

half-inch intervals up to 20 inches from the zero position; this permitsradial moments to be set at five inch-pound increments up to 200 inch-pounds. A one pound weight can be positioned in slots at one inch interval'sup to five inches from the zero psition; this permits radial moments tobe set at one inch-pound increments up to five inch-pounds. A 0.1 poundweight can slide continuously up to 12 inches to either side of zero,and its distance from zero can be read to the nearest 0.01 inch; thispermits radial moments to be set at 0.001 inch-pound increments up to 1.2

inch-pounds. Lest the reader be deluded, it is pointed out, hastily, thatthe theoretical sensitivity of this instrument has been observed to be0.1 inch-pound for the lighter (Littlejohn) warhead and 0.5 inch-pound

for the heavier (Honest John) warhead. In other words, if sufficient care

is taken, a displacement of the 0.1 pound weight of one inch will just

produce a discernible movement of the level bubble when the Littlejohn

warhead is attached. or the same effect to be observed when the Honest

John warhead is attached, the 0.1 pound weight would have to be moved

five inches. For a more complete discussion of the sensitivity of thisinstrument, see Appendix C.

Referring to Figure 3, assume that the warhead is in the general

position with respect to its axis so that its centroid is at position P.i.

The unbalanced radial moment is Wr1 , and requires a clockwise radial

balancing moment of equal magnitude (M I). Now the warhead is rotated 900;

either to position P2 or to position P, (in this idealized situation, it is

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iaterial, as wil be shown shortly). Say the second position is P2 .

Then a counter-olockwise radial balancing moment (N2) is required, of

mgnitude Wr2 .

Thus we have two equations wherein the unknons, rI and r 2 are

evaluated:Wr I = M1 , r I a

Wr2 = 2 , r2 =M2W

Nov the four right triangles, PIOy, etc. are congruent (see

Figure 3). Therefore, Y1 PI = 02 = r2 (= r4 ) and OY1 = 2P2 = r1 (= r3).

Consequently, 12= r12 + r.22

or, = )2 + (2)ZW

Obviously, the following pairs of positions could be used in this

case: P 1 & P2, P2 & P 3P P 3 & P4 - P4 & P1. With the presentation of thisidealised concept, the reader is referred to Appendix B for a more general

discussion of this oatter, when the conditions assumed in the foregoing

do not exist.

II. Design Features

A. Fulcrum

The principle design feature of this instrument is the fulcrum

point, which allows the centrold of the suspended mass to assume Its

equilibrium position along the plumb line through the (theoretical)

point of support. Consequently, the device functions as a pendulum; more

precisely, it may be described as a paraconic pendulum, because the

oscillations are not confined to any one particular vertical plane.

This design of support was selected on the basis that the frictionat the support would be of mgnitude comparable to that of other support

designs. Indeed, it was expected that frictional errors would be less thanthat created by other support designs (e.g., bearings, knife edges).

Another basis for selecting this type of support is that it provides

the capability to measure the longitudinal and radial CO distances using

one piece of equipment, without any additional operations other than the

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\-UPPORTy STAND

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rotation of the warhead.

It is interesting to note that the original design of the fulcrum

was a ball-and-socket affair. However, the slight discrepancies introduced

by the ball Nriding up* the socket were capable of being detected l. As

a result, the socket was replaced by a plane (i.e., a socket of infinite

spherical radius). Figure 4 illustrates the geometry of the error just

discussed. For a more complete treatment of this matter, see Appendix C.

AX13 of SOCKET AXIS of COME

POINT of CONTACT

Fiiur 4.ISPLACEMENT ERROR of POINT *4 SUPPORT.

F 9q.e¢ 4.

It must be mentioned that brinelling of the cone support surface

is to be expected. However, by suitable iiardening of the surfaces, local

strain deformations have been controlled to the extent that the operation

of the equipment is not affected significantly. Theoretically, the cone

point is deformed so that it is not spherical and, it is supposed, the

support surface has a "socket" created by the cone point. Nevertheless,

the data compiled to date indicates that the accuracy, precision, and sen-

sitivity of the instrument are (compared to other similar devices)

negligibly affected.

Finally, the matter of surface finish was considered so that fric-

tional effects would be minimised.

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B. Balancing Moments

A given moment may be achieved by an infini ',nif)ber of combina-

tions of force times lever distance. In the designing of this equipment,

gross moments are obtained by the addition of various fixed weights

placed at fixed lever distances.a. Longitudinal: The horizontal I-beam of the device has

been designed so that slotted weights can be located at either end, as

required. These weights were designed (see Appendix D), so that the

center of mass of each weight Coinciaes with the bottom of the slot.The fit between the slot and the I-beam web prevents lateral movement,

which would affect radial GG measurements.

b. Radial: The ten and one poand weights are capable of

being located at discrete inter4-als, as diaoussed previously. However,these weights are always on the instrument and by virtue of their path,

exert a constant longitudfnal momert. regardless of their lateral position.

In order to achieve final balani , longitudinally and radially,

provision is made in each case for a zidLig weight which can be posi-tioned at the desired lever distance. The effective lever arm magnitude

is read from a scale graduated in 0.O inch. Originally, both weights

were 0.1 pound; however, the longitudinal sliding weight is now 1 pound.

With the weights currently available, it may be necessary, in

some cases, to create opposing moments t achieve longitudinal balance.By this, it is meant that weigh ts may be added to both ends of the I-beam.

The resultant balancing lrngi,tudnal moment is the algebraic summation

of these moments.

C. Levels

Two levels are provided at. the rear of the instrume;t, one

each for longitudinal and radial inclinations. The movement of the

bubble level of one marked divisiror is eqAra.ler.t to a vertical rise cf0.0005 inch per 12 inches, horizontally. Angularly, this corresponds

to 00 0f9 " , or 0.00004 radians.

The selection of te'se levels is conside-ed to be commensurate

with the intended capability of this ir itrument, as evidenced by the

data derived from the various tests, descrabed elsewhere in this report.

16

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The use of less precise levels would be tantamount to taking a piece of

equipment capable of weighing a horse fly and limiting it so that it could

weight only a horse.

The plane upon which these levels are mounted is perpendicular to

the face plate within 0O0r20v. and is parallel to the lines of travel of

the radial weights within 0.001 inch throughout the entire range of traverse

of these weights.

D. Adjustability Features

In order to achieve a muniversality of application for measuring

warhead OG, a *universality" of adjustment is capable of being achievedwith the design of this instrument.

a. The horizontal I-beam can be moved parallel to its lengthand set in a new position. At the present tine, the I-beam is set as farforward as possible to offset the effe,5 of the weight of the fixture to

some extent (see Introduction).

b. The posltic n of the fulcrum point is adjustable along the

length of the I-beam. The intended lc.aticn (..eo, the k dimension) is

such that, for minimum conditions (of weight and longitudinal 00, simlmLtaneously), baancing wculd be achieved from the rear of the I-beam.However, as the weight of warhead increases, and if the longitudlnal Ovalue, including its tolerance, s such 4.hat the requisite longitudinalrestoring moment is incapable of being effected In the intended manner,it becomes necessary to calculate an optimum location for the fv.crumpoint so that balancing can be achieved by adding weights either at tbhe

front or the rear of the I-beam. A detailed analys.s of this feature iscontained in Appendix E.

c. Adaptors: The face plate whI.ch As Integral w th the instru-ment is designed for the Honest Jchn warhead, which represents the mmaxmuE

conditiong for the instrument. The frcnt sarface of this. fave plateestablishes the reference plane for the warheaa&s longitudinal CO measure-

ment. An adaptor is prciced which attaclies to the face plate, and

establishes the refererce plane for the Littlejohn, which represents the

"minimum condition" for the ir strumento Other adaptors to acccmodate otht'warheads must be desigred, as required, and corrections must be made tc

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reflect the effect of the added adaptor on the resultant Ca location of the

fixture. By following the method detailed in Appendix g, the equivalent

of this effect is contained in the general equation to be found there.

3. "Universal w Standard

The standard is an Nartificialw warhead whose weight and OG loca-

tion are known prior to attaching it to the 00 instrument for calibration

purposes (see Photo 2). The calibration procedures are described elsewhere

in this report.

In considering a design for a standard for a device which is

intended for a gamut of warhead weights and 0O distances, two possible

concepts were realized:a. Fixed Type: This is a standard which, by virtue of its

symetry of mass distribution, or simple geometry, permits a desired weightand 03 location to be rather closely achieved. However, this requires a

design with "tight" tolerances. For example, a simple illustration is a

chunk of metal in the shape of a right circular cylinder of known lengthand diameter, with suitable provision for attaching it to the instrument.

However this, and other simple geometries, were ruled out because of theinordinately large masses or enlarged dimensions that result from thisapproach. It must be borne in mind that the standard, in essence, provides

a balancing moment, as does a normal warhead. If the geometry is to be

"machineably" simple, then the weight factor and the CG location opposeeach other. The example of the cylinder illustrates this lucidly. If

the diameter is reduced to reduce the weight, the length must be increasedto inerease the CG distance, so that the required momcnL '.r capable of beingexerted. Not only do awkward len:,thc result, but. ket'kiton6 in the standard

due to its own weight increase to the point of introducing sizable errors.Conversely, reducing the moment arm by reducing the length requires an

increase in the diameter (i.e., the weight) so that the desired moment isachieved. For these considerations, as well as the difficulties which would

remain to determine the true 03 location of the standard, this type of

design was not used.

b. Adjustable Type: In considering the design difficultiesdiscussed in the foregoing paragraph, the design concept of the existing

18

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standard emerged (see Photo 2).First, four pads with threaded holes were required to mate

with screws located by the four holes in the large adaptor, or face plate.

Next a pyramidal type framework of hollow, thick-walled pipe formed a

rigid structure which located the four pads and allowed a concentration of

mass toward the apex of the pyramid. Finally, a solid circular shaft of

steel was added which, by suitable positioning, permitted longitudinal

adjustment of the standard's CO so that it would coincide with its fulcrum.

The photograph shows the standard balanced on its own stand.

The fulcrum, which cannot be seen in the photograph because it is hidden

in a hole in the solid axial shaft, causes the standard, like the CG instru-ment, to behave as a paraconic pendulum. Although Figure 5 shows the

original design as a ball-and-socket, the socket was replaced by a plane

surface, for reasons discussed previously. The resulting precision in

locating the standard CO was observed to be improved.

The two bars extending perpendicularly from the shaft per-

mit a sliding weight to be positioned to achieve radial balance, during

which process the longitudinal CG of the standard is not changed. Adjust-

ment of the solid shaft in a direction parallel to its axis permits longitu-

dinal CO to be varied as desired. A circular level indicates when longi-

tudinal and radial balance exist simultaneously.

It is to be noted that the weight of the standard is constantalthough the CO location -an be shifted. By suitable addition of longer

solid shafts to replace the existing one, the weight of the standard can

be increased, as well as the range of location of the longitudinal CO. In

other words, the design permits a family of standards to be made rela-

tively cheaply and easily, so that a desired standard moment mpy be

selected for use.

At the present time, the standard exerts a restoring moment

in the range required for the Littlejohn warhead. Consequently, relocation

of the fulcrum for larger warheads is accomplished by computation and physi-

cal setting of the fulurum to the calculated location. Ideally, the fulcrum

location should be checked by the use of a standard which physically demon-strates the correctness of the fulcrum location.

4,9

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However, the point being made is simply the presentation

of the idea that, lacking certain physical equipment, specifically, a

standard for each fulcrum location, the shifting of a known starting point

to a new starting point is capable of being accomplished by proper appli-

cation of the principles involved. In the situation described here, it

is reiterated that the principles of the lever laws are being employed to

define the desired modification. If the data and the theory are valid,

and are used correctly, and the modification is performed correctly, the

resulting modified equipment is considered to be useful for its intendedfunction.

F. Handling

1. Instrument: Two eyebolts are provided. In lifting the basic

instrument alone, in a nearly balanced position, the rear eyebolt is used

(see Photo 1). The longitudinal position of this eyebolt is adjustable;

its nominal location was obtained by calculation of the instrument CO

location prior to its fabrication.The other eyebolt is integral with the fulcrum cage assembly

and is used in the event it should be necessary to handle the instrument

with the warhead attached.

2. Standard: The two eyebolts seen in Photo 2 are used with a

bar and sling arrangement to lift and transport the standard to and from

the instrument. They are removed prior to balancing and using the standard.

III. Otling of Procedures

The following outline of procedures is intended to describe the use

of all of the equipment comprising the complete instrument. Bereft ofall complicating details, the essence of the typical use of this equipment

may be summarized: The basic principle of operation of the instrument is

that which describes a simple lever whose fulcrum lies between the two

loads which are applied to the lever. The moment exerted by the instru-

ment is adjusted to achieve a balanced condition, so that the restoring

moment (4) is known with accuracy. The unbalancing moment caused by the

warhead is the product of a known weight (W) of warhead and an unknown

lever distance (7). Therefore, d = N or r = O, and the CO distance, T,

is seen to be a value derived from known quantities.

20

Page 28: AD295 739 - DTICfor 'bulls-eye' capability is particularly emphasited. The design of equipment for measurement of center of gravity location for warheads has been left to the various

However, in order to be able to achieve the situation whereby the

instrument moment is indeed a known quantity, the standard first must be

mated to the ipstrument; now the situation is reversed. The moment

exerted by the standard (M ) is known. The balancing moment (in its

simplest sense) exerted by the instrument is the product of a known

weight of fixture (W F) and an unknown lever distance (!7). Therefore,

or XF = -, and the 0( of the fixture, X , is seen to be a value

derived from known quantities (see Appendix F).

21

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'f4'

'4 -)

'44r4 0 t2. ;0 JO5

A4 0 4 9 $4

rz 4 (UUE-40 t444d~8o. .

14 N:0 4 4* I

So 9

4-) 0 0t ft o a

'4-444J

8)8 00W d f

14 N. 0 A

(14 a4 C1 -N-

.. %.0 Ell*' 0-

-M Jv

0 4; 22

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INDEX TO PHOTOGRAPHS

Page No.

1. Instrument resting on fulcrum and Jack. 24

2. Standard and weights. 25

3. Instrument ualanced on fulcrum, standard in place,

Jack removed. 26

4. Close-up of fulcrum. 27

5. Rear of instrument. 28

6. Instrument balanced with Littlejohn warhead in place. 297. Instrument balanced with Honest John warhead in place. 30

23

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Ci

ramr

Photograph No. 1

Instrument Resting on Fulcrum and Jack

24

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Photograph No, 2

Standard and Weights

25

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Photograph No. 3

Instrumnt Balanced on Fulcrum, Standard in Place, Jack Removed

Page 34: AD295 739 - DTICfor 'bulls-eye' capability is particularly emphasited. The design of equipment for measurement of center of gravity location for warheads has been left to the various

~1a

27

Page 35: AD295 739 - DTICfor 'bulls-eye' capability is particularly emphasited. The design of equipment for measurement of center of gravity location for warheads has been left to the various

r 1

At

r4

4a

28

Page 36: AD295 739 - DTICfor 'bulls-eye' capability is particularly emphasited. The design of equipment for measurement of center of gravity location for warheads has been left to the various

i~.

II

lb

p 4 I4)

29

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Ce.- 0

30

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INDIX TO APPENDICES

Page No.

A. Instrument Constants

1. General Equation for Longitudinal Location of Warhead

Center of Gravity A-1

2. Basic Constants A-1

3. Tabulation of Data for Various Warheads A-2

B. 1. Procedure for Determining Radial Location of T54, M146

or MS Littlejohn Center of Gravity B-1

2. Example of Determination of Radial Location of Littlejohn

Center of Gravity B-2

3. Derivation of Procedure for Determining Radial location

of Warhead Center of Gravity B-7

4. Analysis of Effect of Eccentricities in Adaptors B-11

C. Prectsion, Accuracy and sensitivity C-1

D. Design of Longitudinal Weights D-I

B. 1. Calculation for Pivot Shift .,1

2. Derivation of Minimum k of Instrument and Related Constants E-2

3. Example I - Warhead Assy MIA2, HE, Honest John E-3

4. Example II - Warhead M38, M144, M132, Honest John Z-4

5. Example III- Warhead M38, M144, M132, Honest John E-5

6. Example IV - Warhead Assy X146, HE. Honest John z-6

7. Example V - Inert Loaded Warhead &ssy MI1A2 (Including ' & 1) 3-7

8. Example VI - Illustration of Method of Calculation Where

Special Adaptor is Required Z-9

9. Establishment of Limits of Acceptance for Longitudinal

Location of Warhead CO E-11

10. Conversaion Tables, Balancing Weights to Longitudinal Moments Z-12

F'. Determination of TF. Using Standard F-i

31

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APPEDIX A

1. Derivation of general equation for longitudinal location of warhead

center of gravity.

Xv N

W. , ( FTRE

R ,PIVOT Ia. (REAR)Figur e A-I

For equilibrium,

Vpivot = W1(40.781-k) + W(-k) - WF(X +k) - W2 (23.219+k) - M, = 0

Let MI M W1 (40.781-k)

M2 = w2 (23'219+k)

W

Let N2+"V-Mi = net moment = M

'- w(X 7+k) + Hk= W -- k

2. Basic constants

a. Fixture total weight = 1729 lbs.

b. Pivot cage weight = 36 lbs.c. W. (net fixture weight) = 1693 lbs.

d. Y, (distance, face plate to fixture (G) : 4.389"

e. W1 CG to w2 GG = 64.000 1= s1+s2).

NOTE: All values used refer to the initial position of the beam

in the main cage. If this is changed, new values for X , sit s2, & k will

have to be determined.A-1

Page 40: AD295 739 - DTICfor 'bulls-eye' capability is particularly emphasited. The design of equipment for measurement of center of gravity location for warheads has been left to the various

ot

ba bOj

41-

0 04's l.M 0 1111 4.)-..9E

, +

14 N

41

CY %09-9--

0Y 0

0% 0

- c ~46

C- N M. 0%

44

32.3

A-2

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APPEDIX B-I

PROCKIXRK FOR CTU1MNI0 RADIAL LOCTION

of

T54, M146 or HS LITTIZJOHN CUITt OF GRAVITY1. Balance radially, and read balancing moments, at each of four

positions, A, B, C, D of the faceplate (clockwise balancing moments are

considered positibe, counterclockwise negative).

2. Calculate M, = A~a and M.= MD . Record, disregarding sign.2 2

3. Using Chart BI, place arrow of resultantl strip on value of MV

align edge of strip at M2 Read M, Resultant Moment, where strip edge

intersects the M2 line.

4. Any value of M below 25.3 inch-lb., indicates an acceptable warhead.

For higher values see Chart BII. If the intersection of N and warhead

weight falls below the lower line, the warhead is acceptable. Any such

intersection points above the lower line represent reject warheads; if they

fall between the two lines, consult Engineering for re-check before reject-

ing.

If it is desired to know the actual radial displacement for any

given warhead, refer to Chart BIll.

See Appendix B-2 for an example of this procedure.

B-I

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APPUIDII 9-2

XANIM OF WTU ATICK F01 RAD A LOC&TION OFT54& LITTLZJOIM CDI OF GRAVITY

W - 258 lbs.

1. Momnt readings: A B C D

+25 -22 -5 +182. MIa"25-)- 15

2 N1 2a-22-18 -20

Record as N1 u 15, M2 = 20

3. M=25L. Since N = 25 Is below 25.3 inch-lbs., the measured warhead is well

within tolerance. The actual displaement, sheon on Chart BIII is .097a.

Assume, now, that X had been 25.9, Reference to Chart W1I and travelling

vertically along the 258 lb. warhead weight line, it is seen that N a 25.9

represents a reject. If N had fallen between 25.3 and 25.8, it would be

in the range considered dangerously close to the acceptance limit of

Wu . 1000, and the engineer in charge should personally investigate to

determine acceptability of the item.

B-2

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0

z in C

Z sm 2

zLa2

vLI

0

U- 0

B3

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APPUDIX B 0

RmSULTANT PIEUT STRIPFOR USE WITH CHART B-I

Directions:

Remove strip to right, or use ruler graduated 0

in inohes and tenths of inches, where inch wil

equal one inch-pound and 1 inch will equal 10 inch- z

pounds.

0

0U)

00

- 0

- 0

-0

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TI

-1 4

f 7 1 77 7

~ o4~, Ot4~S -

I-T

*TO

I7<,0_

Ew" -A

Page 46: AD295 739 - DTICfor 'bulls-eye' capability is particularly emphasited. The design of equipment for measurement of center of gravity location for warheads has been left to the various

AXIS of ROTATION

Figure B-t

VIEW FROM REAR OF INSTRUMENT

ADAPTOA

DIAL INDICATOR

IX

WARI4EAD LVCATINf

Fiue B-2

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AFDIZx E-3

MIVATICG 07 PROC NRE FOR IWIDO

RADAL OATIO OF WARHEAD CiTM OF GRAVITY

Any displacement of the center of rotation of the warhead center of

gravity (warhead axis) from a vertical plane through the pivot point will

result in radial moment readings, taken 1800 apart, not symmetrically

disposed about zero.

Refer to Figure B1. The s-axis is taken as the vertical through the

pivot point, and the x-axis is the theoretical zero axis of the instrument;

that is, if the axis of rotation of the warhead coincided exactly with the

x-axis, then y. and YD would be equal in vagnitude and opposite in sin,

and similarly for yA and yC"It my be assumed that the center of the faceplate - the axis of

rotation - is not precisely below the pivot point when the instrument is

level radially. Thus, when a warhead is mounted concentric with the face-

plate, a constant moment will be required to level the instrument, and the

effect of radial displacement (1) of warhead center of gravity from the

warhead axis is superimposed on this constant value. As the warhead is

rotated to four positions successively separated by 900, and balance is

established at each position, readings of restoring moments will be obtained

for positions at A, B, C, and D. When the measured moments are divided

by the warhead weight, actual radial displacement of the OD is obtained,

as follows:MWarhead Position Moment y =

A MA YA

B MB Y

C MB Y

D M

Referring to Figure B!,

F = = = YB2YD

B-?

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The displacement of warhead axis = y0 and

Yo a YA4 p or 70 = Y2221

Ixperimental data has established a maximum yo = .030 .

These operations may be reduced to graphical form, as shown in the

*Procedure for Determining Radial Location of Littlejohn Center of Gravity".

When an adaptor is added to the fixture to accomodate a given warhead,

it sme, in general, be accentrio to the center of rotation. The effect of

this eccentricity can be determined as follows:

1. Measure mechanical eccentricity of adaptor O.D. by use of a

dial indicator placed to read at the right end (looking from rear) of a

horizontal diameter (Figure B2). (Indicator support my be clamped to the

I-beam). Set indicator at zero when faceplate is at A. Record values

when faceplate is at positions B, C, and D. as b, c, and d. Pay strict

attention to sian of readi .

2. Measure mechanical eccentricity of warhead locating surface

O.D. similarly. Record as b1 c1 d1.

3. Compute moment errors as I o2ows

1 2 A

"C+Cl

4. Compu-te mechanical shift errors as Z 3 U34 2

5. Take moment readings at positions A, Be C, Dwith warhead in

place. Record as MA. %. NCO %, conforming to established sign convention.

6. Correct measured moments as follows:

MA731

MB+32

"C+31

B..8

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7. Calculate yA' YB yC yD by dividing the corrected moments

by W.8. Corct BI r arid YDas follows:

YA =YA.E3

YC= YB+E3I

= YDEIJ, YD9. Then 2_ -k~) (BD

+ 2

B-9

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1) DIAGRAMS of 5UCCE551VE P06ITION6P..,4'lon A 0A 4 ECCE~NTRIC ADAPTOR

(Ec4%t%+rlcli4 e41 cxs..a+4 fr 4 aiy

N~~~~. ~~~CE4TETI *4 ROTATION £oqr+i{vcosy

.4 T ~~RROq *4 A A -

DIAL INDICATOR

(1ndkl.C4.r Q+~ ze iro

b()ERROR u+ B 65 bB 2

_ _ __C o C .ER O . ,

Po.;4;on 0c

B-1 0

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APPNDIX B-4

ANALYSIS OF EFFET OF ECCTRICITIE IN ADAPTORS

Refer to Figure B3I! is the actual eccentricity of the adaptor O.D. After setting

indicator at zero when faceplate is in position A, reading. b, a, and d

will be obtained. It is evident that the y-component of this eccentricity

with respect to the center of rotation will appear as eC - f at position C,

*B a at position B, eA = -T at position A, and eD - - at position D.

At position A in example, the centroid of the adaptor is shown with

a y-omponent displaced eA from the center of rotation. This will produce

an error of moment WAeA, shown here as producing a clockwise or positive

moment which requires a negative restoring moment in the instrument.

Therefore, in order to correct the result, a positive correction factor

must be applied. Following the definitions of B1 , U2, , and E4 given,

the correct sign conventions to apply to the corrections are given in the

preceeding tables. A similar analysis applies to any error of eccentricity

in the warhead locating surface.

B11

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APPENDIX CPRECISION, ACCURACY AND SENSITIVITY

Initial testing for instrument repeatability with the standard in placeindicated a mechanical hysteresis, typified by results of a radial balance

test shown in Graph C-I. Investigation determined that the pivot socket was

softer (Rockwell C-38) than specified (R-C-63 to 65). The soft steel bri-nelled under load, and the spherical pivot climbed up the sides of the Inden-tation, shifting the actual contact point away from true center and givingrise to errors of about 4* inch-lbs. (Note that the curved portions at eachend of the graph are caused by the bubble impinging the end of the vial,thus giving an apparently non-linear relationship, since the position of thebubble end was taken as giving a true angular reading while in reality it

did not).

When a flat plate of hardness Rockwell C-64 was substituted, the totalerror was reduced to 2 inch-lbs. (Graph C-II).

A check of repeatability within small angles of tilt yielded Graph C-IIwhich was analyzed by least-square curve fitting methods and statistical pro-cedures. The response of the instrument was determined by this means to be6.1 seconds of angular deviation per inch-pound of offsetting moment. The

standard error of estimate (S y) was established as 0.32 inch-lbs. A range of

!2 Sy includes 95% of all readings; therefore, 95% of the time, any reading

will fall within -. 64 inch-lb. This compares favorably with the value est-ablished by general observation following.

When an experienced operator balances the instrument, observing maximum

care, the minimum offsetting moment which can be detected by noting level

bubble movement is the maximum sensitivity of the instrument. Dividing this

minimum moment (inch-lb) by the weight of the warhead involved translates

sensitivity in inch-lbs to sensitivity in terms of the OG location in inches.

The following table shows observed and calculated values obtained in this

manner: I M

observedt W1. With Standard (324 lbs) -. 1in-lb

with Littlejohn (262 lbs) -. 0003"2. With Honest John (1687 lbs) -. 51n-lb .0003"

C-I

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It is evident that the sensitivity of the instrument, within the range260-1690 lbe is constant in terms of 00 location.

A more practical statement of sensitivity, reflecting values which mightnormally be expected in actual use, is based on the ability to read thelevel to + division with no special care. This is in accordance with stan-dard estimates of instrument reading uncertainty, and also eliminates concern

for minor variations such as might be introduced by temperature changes duringa set of readings. One division is equivalent to 9 seconds of angle; asnoted above, one inch-pound has been found to produce a tilt of 6.1 seconds

with the standard (weight m 324 lbs); thus usable sensitivity may be taken

as

Since we have determined that sensitivity in determination of OD loca-

tion is constant, the .0023* figure will apply as well to the Honest John

warhead, or any other within the usable range of the instrument.The present limits of acceptance for two warheads under consideration

are:

Littlejohn T5-. . 1004

Honest John M38 +2.0000 .125"

Therefore the instrument is more than adequately sensitive to measure

these quantities.

A series of readings were taken to verify response characteristics ofthe instrument. When disparate results were obtained for longitudinal

(5.5 see/in.lb.) and radial (6.5 see/in.lb.) sensitivities, the longitudinalindicating level was removed and placed parallel to the radial indicating

level. A series of readings were taken with small offsetting moments bothto right and to left. This verified the suspected cause of the trouble,

i.e.. the two levels did not read alike. The magnitude of difference is notsuch as to cause any difficulty in operation of the instrument.

C-2

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Z ILW 1

00U

0~a.is < u

00

N 0

C-3

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:! i 9

" I\I)

L'aNo) • NOII.tAIO

*Jj U I-VIV . \

t\r

-, -z <uro

Page 56: AD295 739 - DTICfor 'bulls-eye' capability is particularly emphasited. The design of equipment for measurement of center of gravity location for warheads has been left to the various

Wa IW

z U

J < 60014CDs

(-

z

o.e

05

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APPENDIX D

DESIGN OF LOGITUDINAL WEIGHTS

A

r- gure D

Taking the moment of the centroid of the areas with respect to axis A-Ah. x

1.b I -a(-) = (bh-ax)(x)

Equation 1 defines the depth of slot, x, such that the centroid

of the area is at the bottom edge of the slot, as shown. The values of

a, b, and h are selected by design considerations, and are treated as

constants.

2. The practical solution for the quadratic in x is given by

= h:-Da

For a one pound weight, the thickness, t, is calculated from

3. t = o( ax

wherepO= density of the material

x = value from equation 2The thickness of any other weight (W) is merely Wt.

D-1

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APPENDIX E-IGENERAL PROCEDURE FOR CALCULATING PIVOT SHIFT

The basic equation used is derived from Diagram At.

Equation 1W1 (4O.781-k)+W(Y-k) = WF(YF+k)+W 2 (k+23.219) (Mv = 0)

Take minimum values for warhead weight, W, and warhead CO location,I. For perfect balance with these values, WI = W2 = 0, and the equation

reduces to

Equation 2

W(ZLk) = W( k

Substitute all known values and determine k.

Using this value of k and maximum values of W and 1, determine

maximum W2 .

If this value of W2 exceeds the total of weights on hand, recal-

culate k as follows:

A. Set up two simultaneous equations for the moments which

exist at equilibrium when the warhead moment (f) is () maximum and

(2) minimum.

B. Let the balancing weights be equal in each case, but of

opposite direction. (WM).

C. Solve for k.

D. Determine V1M by substituting maximum N&Y in A(1) above.

The ultimate limit of the instrument is established by the total

weight which can fit between the flanges of the I-beam, or 166 lbs.

For typical calculations, see Examples I through VI following.

E-I1

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APPENDIX B-2

DERIVATION OF UDUM AVAILABN k Or INSTRUNET

AND RELATED INSTRUMENT CONSTANTS

1. Correction in k to account for tapered gap:

L 24.017-1

LOOKING FROM RE DIL. SIDE .01611. SIDE .Of1_Z

(FROM owems.)

SE- I

"018+'012 5Average clearance 0 2 = .015

"015x(13"75+1.907) . 01Projected to pivot point, 13.75 17

Design value of ko (verified by parts inspection) = .781

Corrected ko - .781+.017 = .796

2 = 24.000 (design) + .017 = 2 4 .0 170

S = 64.000 - 24.017f - 39.9830

Faceplate to CO of rear weight - 24.017-.798 23.2199

Faceplate to CO of front weight m 39.983+.798 = 40.781

E-2

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APPENDIX 9-3Example I

Warhead Assembly M1A2, HE, Honest John (Dwg. FXP-107671)

W min = 1657-12 = 1645 lb.

nominal = Sta. 115.000 - Sta. 89.160 = 25.8&0

min - 25.84-.5 = 25.34K

W(I-k) = WF(7F+k) (Equation 2, p E-1)

1645(25.34-k) = 1693(4.389+k)

k = 10.262"

wmax =1 669 max =26.34 W= 0

W(-L-k)-VF(7k+k) = W2 (k+23.219) (Equation 1. p E-I)

1669(26.34.10.26)-1693(4.39+10.26) = W2(10.262+23.219)

W2 60.784

Since 116.8 lbs calibrated weight is available, this is well within equip-ment capability.

E-3

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APlEDIX &4.

Example IIWarhead M38, MI44, M132, Honest John

w min = 1625-12 = 1613

Y min - 35-2 = 33

w(Uk) = WF( +k) (Equation 2. p B-1)

1635(33-k) - 1693(4.389+k)

k w 13.922

Wmax = 1625+12 = 1637 V1 =0

max= 35+2- 37(Lk)-Wr(!,+k) - W2(k+23.219) (Iquation 1. p L)

1637(37-13.9)-1693(4.389+13.9) - W2(13-.9+23.219)

W2 = 184 lb.

Since this exceeds the 116.8 lbe available, determine best k by simultaneous

equation method described in Appendix B-1. Appendix r-5, foloring,

illustrates the method by an example.

Page 62: AD295 739 - DTICfor 'bulls-eye' capability is particularly emphasited. The design of equipment for measurement of center of gravity location for warheads has been left to the various

APPENDIX E-5

Example III

PIVOT SHIFT TO ACCOMODATEHONEST JOHN WARHEAD, M38, M144, X132

(W = 1625t12 lbs. X = 3 2inSteps A& B (See p E-1)

I W(40.781 k)+W(Y-k) F(70 k,- 2(k 23.219) = 0

When W = max value = 1637 lb and X = max value = 37k, then

WI = 0 and W2 = max value = WM.

1637(37-k)-1693(4.389+k)-WM(23.219+k) = 0

Ia 53137-3330k-WM(23.219+k) = 0

'When W = min value = 1613 lbs and = min value = 33", then

WI = max value = WM and W2 = 0

WM(40.781-k)+1613(33-k)4 693(4.389+k) = 0

Ib 45797-3306k+WM(40.78 1-k) = 0

ialtiply Ia by (40.781-k) and Ib by (23.219+k) and add to obtain

k2-9162.6k+134,595.3 = 0k 9162.600!9133.176

2k = 14.712 (Here we utilize the answer resulting from the negative

second term in the numerator. The answer resulting from the positive

second term in the numerator is rejected as being physically inapplicable,

although mathematically correct).

Substituting k in Ia, we obtain

4M = 109.17 lbs, less than 116.8 lbs available, and therefore satis-

factory.

Pivot shift = k-k° = 14.712-.798

= 13.9140

Aeasurement of new pivot location is made between lower forward edge

of main support cage and rear edge of pivot cage (at left, looking from

rear of instrument):

d = 13.914+.018 = 13.9320 (See Figure 9-1)

E-5

Page 63: AD295 739 - DTICfor 'bulls-eye' capability is particularly emphasited. The design of equipment for measurement of center of gravity location for warheads has been left to the various

AMUDIX s-6Example IV

CALCUTION 0F k FOM WARHEAD ASSEMBLYx", H, HONSIT JOHN

(Drawing ?XP-107672)

W min = 1657-12 - 1645 lb.

nominal - Sta. 115.000 - Sta. 79.715 - 35.285?

in 35.285-.500 = 34.7850W(Lk) = WF(fXF.k) (Equation 2. p 3-1)

1645(34.785-k) = 693(4.389k)

k a 14.915'

Wmax = 1657+12 1669 lb. WV a 0

I max = 35.2854.500 = 35.7850V(--k)-V,(!l+k) = W2 (k+23.219) (Equation 1. p L-1)

1669(2o.869)-1693(19.3o5) a w2 08.135)W2 = 56.3 lb.

d = 14.916-.798+.018

- 14.916-.78o

= 14.1o6 (See Figure E-l)

9-6

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APPEIDIX E-7Exaple V

CALCULATION OF GG LOCATION FOR

INERT LOADED WARHEAD ASSM(ELY MIA2, HE, HONEST JOHN

sured oiht W = 1687 lb (design max. a 1669)Nominal design 1 = 25.84"

W(Lk) = WF(YF+k)

1687(25.84-k) : 1693(4.389+k)

k = 10.699

Desired Measurement = k-.780 = 10.699-. 780

= 9.919

Actual Space Measured = 9.957

Actual k = 9.957+.780 = 10!717Pivot to rear balancing weight = 10.737+23.219 = 33.956Pivot to front balancing weight = 40.781-10.737 = 30.044

WI(30.044)+W(Z-10.73)-WF(4.389+10.737)-W 2(33.956)-Mv = 0

" " '(15'126)+2(33956)+M vW(3,044) +0.737

W= 1693(15. 126)+16.006(33.956)+1.5...248(30.044) +10.737

1687

= 26.235

Design max! = 25-.84+.50 = 26.34"

CO longitudinal location is within tolerance.

3-7

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gzap. V(a)

ChAWIATIONS FROM ADDITIONAL DATA FOR

INERT LOAED WARHEAD ASSEMBLY MIA2, HE, HONEST JOHN

W1 = .248 lbs N1 = 7.45

W2 = 16.006 lbs M2 = 543.50

N = 3 (in) to 11.3 (=x)' 6.5 (&vg)

See previous calculation for this warhead25608.30+5Q.5-6.5-7,5+

1687 1073

= 26.238

Max unoertai-t in = = = .oo28"

Data: M= 5 4

MB = -38.5

MC = 14

ND = 117

2 - 2 =

Mresultant = 80.4

= "resultan.81.1

= .04771

E-8

Page 66: AD295 739 - DTICfor 'bulls-eye' capability is particularly emphasited. The design of equipment for measurement of center of gravity location for warheads has been left to the various

APPEDIX E-8

Example VI

ILLUSTRATION OF METHOD OF CALCULATION

WHEE &*'CIAL ADAPTOR IS REUIRED

Z:termination of CO location of Inert Loaded T-54 Littlejohn Warhead64"64-k-1 -23-21,9"

The general equation is:

INP = , = 0--P W(1. -.?98)+39.983W,.W,(.798-Z,)-W,( ,,+.798)-24.o, W-M_ 0_ _

A = 1.264' (From Dwg. 8849043 and inspection report of adaptor dimensions)WA = 92.7 lbs'A = .4660

w7 = 1693 lbs

= 4,.3890

is the distance from the faceplate to the warhead reference surface

av determined by the adaptor.

w(i+.466)+39.983 1.92.7(.333)-.1693(5.187)-24.017W 2 -N 08 8 1 2 .4 6 1 + 2 4 . 0 i 7 2 + "v - 3 1 _8 4 6 6" W"'

Set up charts to read M2 = 24.017W2

= .39983W,

Then let M = I2+M(v- 1 and K : 8812.1 +! .

E-9

Page 67: AD295 739 - DTICfor 'bulls-eye' capability is particularly emphasited. The design of equipment for measurement of center of gravity location for warheads has been left to the various

W2 = 7.001 i. - 168.,14

K,. 16.o

1804.24

1 = 61.oo6 M1 ,243.20

S= M2+v-M1 -2254.96

W = 253 (this unit was missing 2 flashcharges, thus was underweight)= 8812.46-22%. 466

253=25.4530

-10

Page 68: AD295 739 - DTICfor 'bulls-eye' capability is particularly emphasited. The design of equipment for measurement of center of gravity location for warheads has been left to the various

APPMUDX 9-9Istablshment of Limits of Acceptance For Longitudinal location of Warhead 0aI. T54, Ni46, ms Littlejohn

From APPEDIX A-28812,461 .66

N w (!+.466).,m12.46iThe following values were used to oonstruct Chart B-I

25 25.9 -2010.05

25 26.9 -1752.05266 25.9 -1799.12266 26.9 l533-.12

II. M38, f144, M132 Honest John

From APF1DI A-2=3 - +14.712

WN W (XL1L.712)-32337.993

The following values were used to oonstruct Chart 9-LW i m

163? 33 -2400.031637? 3 +47.97

1613 33 -2838.941613 37 +3613.06

3-11

Page 69: AD295 739 - DTICfor 'bulls-eye' capability is particularly emphasited. The design of equipment for measurement of center of gravity location for warheads has been left to the various

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Page 70: AD295 739 - DTICfor 'bulls-eye' capability is particularly emphasited. The design of equipment for measurement of center of gravity location for warheads has been left to the various

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Page 71: AD295 739 - DTICfor 'bulls-eye' capability is particularly emphasited. The design of equipment for measurement of center of gravity location for warheads has been left to the various

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Page 72: AD295 739 - DTICfor 'bulls-eye' capability is particularly emphasited. The design of equipment for measurement of center of gravity location for warheads has been left to the various

DETERMINATION Of XF, U51NG STANDARD

XI JW~, s 693*

R5 1..900 tOOt

A4 balance$

xm()0 aWF (xF+ .798) % WS ( 5 - .795)aW.(10-.79") -798

31Fwp324(1.7.101) _ 9

16I 93

a4.389 Inches

F-1

Page 73: AD295 739 - DTICfor 'bulls-eye' capability is particularly emphasited. The design of equipment for measurement of center of gravity location for warheads has been left to the various

DISTRIBTION LIST

Copy No.

Comanding Officer I - 6Picatinny ArsenalATTN: Technical Information ServiceDover, New Jersey

Commanding General 7 - 8U. S. Army Mmitions CoainndATTN: AHNSJ-A, AMNU-WDover, New Jersey

Commanding Officer 9 - 11U. S. Army Missile ComandATTN: Scientific Information CenterRedstone Arsenal, Alabama

Commanding General 12 - 16Army Material CommandATTN. Technical Information ServiceWashington 25, D. C.

Armed Services Technical Information Agency 17 - 31Arlington Hall StationArlington 12, Virginia

Commanding Officer 32 - 43Ammnition Procurement and Supply AgencyATTN: SNUAP Technical Information ServiceJoliet, Illinois

Commanding Officer 44 - 45Diamond Ordnance Fuze LaboratoriesATTN: Technical Reference SectionConnecticut Ave. and Van Ness St., NWWashington 25, D. C.

Commanding General 46Aberdeen Proving GroundATTN: Technical LibraryAberdeen Proving Ground, Maryland

Commanding Officer 47Rock Island ArsenalRock Island, Illinois

Commanding Officer 48Radford ArsenalRadford, Virginia

Page 74: AD295 739 - DTICfor 'bulls-eye' capability is particularly emphasited. The design of equipment for measurement of center of gravity location for warheads has been left to the various

Copy No.

Commanding Officer 49Aberdeen Provng GroundATTN: Ballistic Research labAberdeen Proving Ground, Maryland

Conanding Officer 50Jefferson Proving GroundMadison, Indiana

Comanding Officer 51Joliet ArsenalJoliet, Illinois

Commanding General 52 54White Sands Missile RangeNew Mexico

Commanding Officer 55Tura Test StationYuma, Arizona

Commanding OfficerWatertown ArsenalWatertown, Massachusetts

Commanding Officer 57Iowa Ordnance PlantBurlington, Iowa

Commanding General 58 - 59Defense Atomic Support AgencyWashington 25, D. C.

Commander 60U. S. Naval Weapons IhbDehlgren, Virginia

Chief, Bureau of Naval Weapons 61 - 63Department of the NavyWashington, D. C.

Directorate of Research & Development 64 - 66D. C. of S., DevelopmentU.S.A.F., Washington, D. C.

Commanding General 67 - 68A. F. Special Weapons CenterKirtland Air Force BaseAlbuquerque. New Mexico

Page 75: AD295 739 - DTICfor 'bulls-eye' capability is particularly emphasited. The design of equipment for measurement of center of gravity location for warheads has been left to the various

Copy go.

Ccinndin General 69 - 70Foreign Salnce and Technology CenterArlington Hall StationArlington, Virginia

Jet Propulaion laboratory 71California Institute of Technology CenterPasadena 2, California

Miller Research Laboratories 722832 Naiael StreetBaltimore 30, Maryland

Page 76: AD295 739 - DTICfor 'bulls-eye' capability is particularly emphasited. The design of equipment for measurement of center of gravity location for warheads has been left to the various

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Page 77: AD295 739 - DTICfor 'bulls-eye' capability is particularly emphasited. The design of equipment for measurement of center of gravity location for warheads has been left to the various

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