SUNCLASS• I•h iH

AD 4 6 4,1 65 2

DEFENSE DOCUMENTATION CENTERFON

SCIENTIFIC AND TECHNICAL INFORMATION

CAMERON SIATION ALEXANDRIA. Y',GINIA

UNCLASSIFIED

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 whatsoc,,er; and the fact that the Govern-

ment may hp'.e formulated, fumnlshed, or in any waysupplied the said drawings, specifications, or otherdata is not to be regarded by implication or cther-wise as in any manner licensing the holder or anyothec ptrsur: or corporation, or conveying any rightsor permIis:•ir to manufacture, use or sell anypatentt.eý i!vention that may in any way be relatedthereto.

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C.,HYDROMECHANICS, STRENGTH OF SILVER-BRAZED . ..PE JOINTS

I UNDER DYNAMIC LOAD71 0

AERODYNAMCIrO by

S. Zilliacus

MECHANICS L T

t0

~~l, Fr'*.- n ~

ci .... ,-.

JUN 7 1965

APPLIEDL~ ATHEMAV( $ DC-lZA E

o STRUCTURAL MECHANICS LABORATORYRESEARCH AND DEVELOP.ENT REPORT

~ AC.OUsSTICc& ANDlVIBRATION

April 6

STRUCTU1965 R.p.r. .,,-,f

B~estAvaillable

COPY

STRENGTH OF SILVER-BRAZED PIPE JOINTS

UNDER DYNAMIC LOAD

by

S. Zilliacus

April 1965 Report 1972S-F013 10 01

Task 3974

TABLE OF CONTENTS

Pag.

• 11 ST R A C T .................. ............................. I............. .. ............ ............................. .................. . . .

ADMINISTRATIVE INFORMATION ...................................................................................

IN T R O D ITC T IO N .............................................. I.................. . ............................... . ....... ... .

DESCRIPTION OF TESTS ..

D ro p V e h ic le ............................................................................................ ...... . .......... 7)

T e s t S p e c im e n s .............................................................................................. .............. ... . ....In s tru m e n ta tio n .... ............................................................................ ...................................... 3

T E S T R E S U L T S ...................................................... ........................................... ...................... 3

DISCUS$ION OF RESULTS ..................................................................................................... 4

Permanent Strains ...................................... I ...................................................................... 4

Stres. in Pipe at Joint Failure ............................................................................................ 5

Impa '•! ind Rebound 'elocitie• ...................................................................................... ... 7

Pla!tiv. Strain Energy in Pipe ............................................... 7Pos.-ible Efrtc.v of B ,ending and Internal Pressure ........................................................ 9

CONCLUSIONS ....... ............................................... ................................................. 9

RECOMMENDATIONS ........................................................................................................... 10

ACKNOWLEDGMIENTS ........................................................................................................... 7

REFERE.NC E, .......... ................................................................................ ............... 7

LIST OF FIGURES

Page

F igure I - Seition of Drop Test "ehich . ........................... ...... ........................................ 1

Fi'itre 2 -. Drop Test V'ehicle Ready for Reiease .............................................................. 12

F igure :.1 - F ailed I-Inc h Spec im en 1.................................................................................... 13

Figure 4 - Typical Revord of Tensile Strain. Acceleration.a nd B e' nd ing Stra in ......................................................................................... .. 14

Figure 5 - Pipe Stress at Bond Failure ..................................... 15

Figure 6 - Pipe Stress during Initial Drop ...................................... 16

Figure 7 - Mlaxim um Value of Pipe Stress.......................................................................... 17

Figure s - Rebound Velocit% versus Impact Velocity ofD rop T est \e hicle ........................................................................................ . . Is

Figure 9 - Plastic Strain Energy per Unit Volume in Pipea t Jo in t F a ilure ............................................................................................... . . 19

Figure 10 - stress-Strain Data for Copper-Nickel Pipe fromStatic and Dynamic- Tests .............. 2. 0

Figure I I - Prolx ,svd Coupling Design C hanges .................................................................. 21

LIST OF TABLES

Table I - Dimensions and Areas (of Pipe and Couplings ................................................... 2.2

T a ble -. - T e s t R e s ults .............................................. ....................... .................. ................ 3

Table 3 - Pipe Loads at Bond Failures - Static Test Data ...... 94........................................ 94

Table 4 - Comparison of Ultrasonicallv and Visually ObtainedBond Percentago ............................................... 24

Table I - Flex ibilities of "Parts" of Spe.imens. ........................................................ 95

Table 6 - Approximate Relationships among Flexibilitiee of"Parts" of Typical Spocimens .................................. 26.... .0

imi

ABSTRACT

Do2 s( !u(I i V iI~lymuni i loudi i st s we're vondluvif (tit mix-vinto-nm or coPlpper-

nt- ki-I pipt' joi ned( Iio roti z'. *1)oliping- by Iritule, Ill"II siter. hraa',. utiy liKnds.

"!'lhv 1-ond itrtits %wias i' rroitm 1) tol hn Il'vrI'4't or hi' t1 at surraser'.- aviluIable for

lvs' lrv oc- I n'(t.erre' it,1it boIndIii. ( rawki l of' I Iit- votpling -'orni'timies1WVcnlllI;ivdi(( nonrd h'iiIlire'. lit n vms,vcI:E %V" Oho're. nuplr or' (hi. p~ipe. Sincs' mfaffv

joint frsi I rs's ilapprilrsIiI ws'rs i nil ut-m -dl lay, i coupling geoinetry with F ubrupt

chagv in cross s-~t'ti ol. it modisfiodiii vimpisiig iii'sigto is proipo-edi.

TLhv' (i~tllaic lorcevs rt'qiirm'i isa pr fuje iiilurt' sir silvuer-lmnr,.,. joi, fs

havi ng I ('55 I han .10 )pvre('tli ond tiers' co iderisbly sinai I r 1han sititti ftii Iure

lok in tests- vondlt-itmt ed et sew hvrs on nail atr sp-cin ms's. For joints Aith morethan a bout 60 I'rs'nt Ixitid, tilE' dy~inaic ioe vaO( l ties were of thi. sairnf- mnagni-

* : tide as tho static loadis.

.Joinfts having more than 6 1 p(,r.,('nt laond' aitime only after con?,iderabli-

vlongation or (irt(li pipv. F'or surrii (lenty greait i nit iali dynamic- rorve~. joint rail-

ure occuirred( immledli at ely: ot hermi st tw.%o or more loatdi ngs were required. Im-pac-t vt'loc it ls is~sovi itt d'l hi~ joint riiitire's riangetl from abiout 1 .6 to about

It appo':rs t halt lt'e current pract ice or rejec(ting joints having* less t han

601 pt-rven'! bond is usoit ifi' for d~ynamt~ic loadling.

ADMINISTRATIVE INFORMATI'ION

'IhesoI tests5iier riec(,tl~nlen( to( theI ii Buroau of mp Iii p letter fromtOtt-

David Tavlor %odel Basin (S(eni. l o-1~(r 4I Octobe(r 196:3). Tite wvr. was tinder-

taiken a S Task 397-1 of Project .14--01:1 10 01.

INTRODUCTION

Dynamic load tes5ts of repr(.svitat ive shipbJoard type --i lver-bra:zed pipe conntections

%vere condlu'-tsd att the David Taylor Model Basin after si Iver-lbrazed pipe)t joint hondsl had

failed in servici, dluring shock tesis or operating ships. The data indicated rhat thi'so jointshad low liKnd percentitges. (fiat. is. !he si Iver-laraze bionds covered arvas which wor=-4ftiall in

comp~ari son with the totaul surfa('es aviiiIahle- for bonding.

The bats ic hjti eof the i tat estigat ion wits to ti nil it reint iotiAhi p bet ween, joint

,arength under dynamic loJadi ng and bond pe-rcentage.

%it si'rti', 4isI I '! t -1i'r ':rrti'u ow . 'l'It,. i In tIt I . #rii. 's' 11, sIi' , 'I jfI'i to, . t*rms i i'

I Iss dI'nnuiiie .strvi','it It s joilitt' (%s's h i h'~ im 60r til ifrce'rit howlas) ,.'imiii;r ItoIu~u shcos tsI .:

't v N 'rint! nors' than t hi'tu trnintn ru'qutrvi'u pre,;trirt tu r (I,, nva iiiiiav igid'''re tmi riig ;ir',,..

-I h'': r 1rorc %%:s :1 trtingi -d. 11 "s' ive' ~i'Nti'4'ti'd tl11ugi Itli Iutsujiing 's'sid~d Ito' r',e.. ifrr I,. ot ;a

- v% or sr. lIip~hollrtI shtue11Ik t'ottulit ion n sttIi ltistlsl d pritP% till- itt'''t'tl rlittaihi uifo'rtigf I1 l'nsu,

-¶ri-m-vt h ofl' hi' oi'loft-lei't 11.

ms a:- rk'q I irod(. In econs4 ~inanvo'i wit Ill vurrvi'n prat-I ice'. Iit wIts pflt.I IIIbs:''d I 1at I,' It, fist rj( $is

!.",I failI. i.t.., thl- litstiil illn ajoint luilst ho'&stiut (If w ol'Iop~firi! Ihi, till ijiale' -fro-nvrf I! of fit,'

~ (oni'I ill.! PI'''tir fliii tlL.

DESCRIPTION OF TESTS

DROP VEHICLE

A~' dirtu 'i % v h ' -1 s~, :1.4 niriuct i -f s I)vi 111 - ~I I Iv Itest I he'MS' ste- .if--:I Ses on:.r~ r#, I r r,

;s-ir fosr le'-tin i ,fv Ilit,' ;imcittilz'i of tw%%o re'tsiasnin 1,1 fIirt mvs'. ( )n4 ' I' nn w % i' ý atsI if -titii -41

's' 0'it ithi'- (it her to I iti ' remft(%Iils' Ie top 4 1 rt hli' v i'hI clev. 'l -Iii' us4e'nulh' I s' I nýI io'' eri'd -i nt 14

-ds'ist ve and I hei tspi blsssts't- s'sn- d-i'tnilt :t thf' I i't- 1ttTI arlge'liit't are given in Fivi&ite-s I andIr

2. s'ufhc teni. c! 1iaranv as's' a r,'s tci"Id Ioie'o%' Ilh(' suspended weight to prs'd i'd' its~ contacte

' 'sil:lei hositot:; ()' ;ho' ý.-[shi whi'.' Iliii' spevinasn %%-tts itltlt'.

1:4)r eacl' , '-it. ii, druop vishi c o "a's r:ti :( ra t e known di sitance andi dropped onto tin m

I:%- pla bys i' t rippistr:, :m a eI.-!ric~ reta- n'ii't.s'han isin (Fi gure' 2). Upon imnpac(t. I he sp('(ll'ttnu%.:t- 11N'civie to a tensile' sln r oircirs equal to the prodluc't or t h(' suspet.cit'u nio'ss and its

:oe'tleral ion. th'[Il dymnsic Iv n itt' ftrcs in the- pi it. wals triinsrerred infto thE' coutpling priim-

r'l is'h% nisans of ' heai j rcfe in the bond. ir jo int fujiiurt didi not ocue'ir. the, suspe(nded'

-(1:Ms'iI~t4 itd wssithb a charac-isten:tiic frequu'nuv which dopended matinly on hrv st ifIt'no's or

I h-' ýpoiv nnen-, rind 1 eIntl -Ili i gI itlile'- of 1114' sUM pt'utltu mauss. *s inv(e' the 's'(ili iel' was several timaeý.

li.':c's ir atnd -Mtirffr t han the'- wvi'i ti!v'c q~vim i-n(t.

TEST SPECIMENS

'i'Mars' 1' anu Na's a! Shi pyatrdi. 'ssh ich had l'e'i'n fthuriciat ing '.:iitniI:r spu'c't re.- tor at

tf M ý4atit -.tri'ngthI tq'st!..' fturnishedu 33 -41i'ttmiiot1M niget ho.r withI infeirtmot i tinl thi

114eri's'ptuagrf .~r ipstru in e'iu's jouint. The spi-'s' vise'l co'itv11$i'u or 70-30t voi'rpsrt-r-icvke pipi''1

atndt I 'rs efzu votupi;iIngs jus~iejim 'ss io ('irnds Ill si Iv#.er-hrns(.e 1t ioy. "

t1'~pfetences uare litse'd on page 27.

il ho sp'timitri'n ari' jgi vi lin iublh 1. Ti'm Iwmif pf'rv'4'nitueI or' 9ati joini, ,4 di-lv~'qrmtrIg ri

1,,. n rltr4itsimi itispi-v'41 at)1 MitNlrie I-boid \.I ill SIhilovitrid. i., -diemon it- 'Tabble !

INSTRUMENTATION

bin.ii tittti'io Ol (11 t4)ti.s5i4' iii';mi i~iubq 4rinaif 4 Iv'~ittiI- I~~I.~; u

lm r rinltu'' ( Fhi±r.' 1) and., inl -'oliii' iasol... t4'rIsih wt nil ho-'iuiri, i roiin LoaL'e- :atincho''t at tl

.-i'twir:4 tit' th piii' :,v)P tiI ifls 111141 1111. visiiiil iiil. 11wiii' A J klIfi' s' powi-ro-a I) by varr'-rn.r amrpli-

idl dii'i it-jphY ir [) ho' outtjlit signa.ilI '% gimI froml a , itinii1 rork (1-6 11. tior -.% s a-4 ' tiv-dsgatfi n I

Tlioi ri'Iordititt!. h~-o ad ant -1 :v~4titiaiiv blat rrmiumbicsPl rv'-()ioo-ý- f'romn directI climrri't u)

7t1is v'p- . and ( !io it: ratlm I udimii l~i IIIei i1 brititl4ev 4)f a 41)00 illwi4I 11-ý p-t1.iofl -4 wa- sabont 3100

cp-. T lt -d tritt I f- I % 1.1ji '. I--%%t- (itie-iui.' I() I,;i, a i it fro4 1 1-(I i -n ::- % 4-i ra I IittivI .r- a e I hit 1 tha ioatý

('*Cii'1' tho %whi u'il ';a'vi tnt-r

TEST RESULTS

Bondtt aii trt' mtt~im-drit ini va':w -4poie't'n to'tv'il to ~ aT'htu- o. iv#tr wo'ri. no pipt.

mupluim-. hill (rati-k, (it'l t hi ct-tiplimt -. did oc-tIir in five'=)'~il4f- Whomn tht' rnaLnitude' (if

tI hI' iVmiti :orti' wai- muad' srivivtioi v girvat. joints r:.ilo.i dluringtz w fbirsFtI loadlingi. Ot h'r-

mo r ir t~r'~- Ur- nplbi cat ion-. wt'r4 :'quirt'd for joinrt sepjarat ion. In some c-aso''.. rt'-

pi-alodi~~ : 1?hcam ofif appi prmiit:it ly i'titlb l4)r('t' rq'stil C oti in bond1( failure'.

Fci r !-.- !'tit ia -;!0riia- of' I 't!- (iiftwilh Ivas s t han about' t'f) perce'nt bond). pi'rmant'nt

;I iial iIot*irntwIacPn itt [('55 thaii ahi)U ~2 pa'rcofl oet(-trrm'4 in [i( 11'pipe4 -zoCtiofl5. For, the sa'cond

ýt-nliv (4 a a - i t a''rhan allow. if) p4'rvet' Wind). pormiiaflent p i'w strai ns of up) to aibomi

10 1(, 4r(-t'flf :'i~i~i an a1llou1ittt 41 p4'rt-4' tirt-ttnifirt'nt ia look plac14.4 inn! were *'4'(onipanied hy

penanteni c'ircu-lirli r'r l cab upipn~g s~train orS 4 l)(i to aibuti :1 jwevl't''n thcy tirt'uniferent iat

'ritiri rg 4out"' of th. votillj-t wa ac:ctotlllniifi in( fi%-i cae. byt cIS' 1~ rac-king tat the reentrant

-o~rnf'r in thv s bo(ut dt'r: z(*(- Figurv' :1.

A rv'prtsv'nfaf lvi- osciI tagraiph r'c-orh froim a drop test. giving acco-teration df the lower

1'Ianj!". and 1)0th Ia'nsi I a and he'fdill- Stug sii in the pipe is shown in F~igure 4I. As t'xpevciott.

avvviv 4rat i tn and tf'n!s do stIrain t ime1 hi sloria's art' s ito ii r in s hapte and are' in phitse'. .- rt

noni eongt~fWfion or t h4 pipe is i ntlivalv [I-at h byI t' ro shift in t he tensile !it-t'trin rev-trd.rhr'

was ailso p),'rrn an'n t d('r4rmtlionflu) e 124 4)14 toolbnintg. i ndia-t i ng yi e'bd int! in I ht pipe to retlieve the

i'044fl ni ciiN~ or' titi' sp 1'v1ilmt'.

t'Four 1-in. unil two,' 3-tn. -I4tpifimenq were wit wtrttcd ' k~tttl t-wce4rc io e.touaitiat' iwt- v'ndit ittippel'. r.'wrt't'tety in

the! reaituning fiunen', t)um reiuving the fores;t .xperictinvt' by the joinfoo.

.3

Table -2 giv'ts thie hl'ight. of drop, pieak iicel'hration and duration, dyn..,ii, lual, undi

other pertinent values for uach drop test.

To pre),•int the iltitt fromi I-in. and .3-in. ,lpisiinIfil togellthr, plots we,rt, nipsnt tiingt ,nsile stress in 1he pipeit, as thi ordinaltus and uhlrasonicially obtainod Ixind pcorentiigi.s as

hei, absci.ino. Figures 1, 1;, and 7 give stres, in Ifl, pip(- at fiailun' or i1h. join t , during the

first drop. ind when it renahels its nmaxitmu ii Vtie., respet.ivoly. Inelifded rfr nompariton in

Figure .5 tint static t.st data.2 which art, also li stod in Tablh :1.

Representatit i ve vidu•i. or imlpac and rehinund vfblot.iti(.s or tl., drolr vehiele art, 4hown

in Figure S. The maxilnumi impact vw'hcci(,i r,(luirid to c.ause failure werv abolt if) fps for

joints having less than 60 percent bond and ihout :1I fi•s for joints having mor,, than III per-

cent hond.

Final lv. the plastic- strain (energy pr uinit. %olumv, absorbed by t~h(, highly ductilt, pipe

sect ions has lveen plotted against the, percentage ul bond in Figure 9, totgether with (compara-ti~v statie test dat110.2 The strain energy was ohbtuind by intograt ion of ifh. area undehr astress-strain curve (Figure 10).

As a chock on the, ultrasonic miasurement, n. a visual cs. imate, was math, of the bond

areas of sele.ted spec imen., after thhe joints had failhd. Table I .gives ultrasonic,:'!, arsicd

Visualily obtained hond percentages for cont1iari soil.

Each specimen was divided into "parts'" consisting of the clear length of pipe be-twe,(,n flanges. so(ck(,t of coupliig plus braze metal and pipe inelud(,d therein. and the barrel

(rvmaindhr) of the co'upling. Tin, approximate relationships among the flpxihilitie, of thp"parts•' of the s.pecimens were calculated and are given in Tables 5 and V.

DISCUSSION OF RESULTS

PERMANENT STRAINS

The, drop tests induced svv(eral type.s of permanent deformation, natiely. bending.axial. and circumferential. The eff(,et of biendtng did not appear to reduce, significantly the

ultimat(, dynamic strength of any specimens. Since the pipe material is quite ductile. thepipe s. ply relived itselIf, by vielding, of an': eccentricity in the specimnen.

On the other hand, large p)ermanent axial tonsile ,;train in the pipe was significant.giving rise to considerable cir(cumfferential shrinkage or "neckina down" which extended tothe, coupling, where the abrupt change in section ca;used it severe strain disconti nuity, so.-Vi-i,tir' 3. While( "necking flown" or the pile was taking place. the coupling socket was ex-pt-rien.ing permanent cinraunrnf.ra'ntinl hvr..ih, i"srains, i.e.. "flaring out." elite to the ieccen-

tric' "'ip-joint" action orf ihe brazed (conietion. "Necking down" of the pipe together with" fliring out" or tiit .'oupling probably caused con%4ideradle tensile strre.s hbotweet pipi' and

.oi pling at the alhrupt chonge, in s'ction. ihus, railurv may have otccurred due, to tens.t•eand .4hear stressas actin,, in co,,bination.

-I

Thur it iii.ty his een (hat, undeisirahhl, geomnnetry or tlhi eouplings (sand or otihir stiilair

cast flit ings) 5 prohbaly reduves the strf.ngth of braved joints. A revismd .oupling conrigursa-

tion whit'h lacks stome of this &riiit'nviis I)rtsont. in thi i existing densign is shown in Figure

I i and int-ludes Iha, following changes:

1. Rounding all reent rant. corners tW due'reaso stlrtss cone(ntr•tions.

-2. Increasing Ishe thickness or tis. socket. to presve-nt if^. snflaring out.."

:1. Iemoving material at. tlhi r'nd of this socktt to provide fror a moro gradual channge in

cross stection betwtwe(n pipe ital an.ouplingi.

STRESS IN PIPE AT JOINT FAILURE

Since the ratios tof pipt, and coupling svtctional aretns to 100 percent bond iareas are

ablout the samu, ror 1-in. ad 3-in. pipe (Table I). use orf stress in this pipo. as a variabhi in

Figures "1. 6. and 7 is just ified.+

The data of Figiur(, .5 indicate that for joints having honds orf hess than 40 percent.

the dlvnaiiut force required to produv, failure was genrally much smaller (often by 50 per-

cent) than the static force. 2 Also, the :3-in. speimens failed at at lower static atnd dyna.:,,.

etnsihe stress in the pipe, than did thes I-in. specimens.

For joints having more than about 010) per'ent bond. the dynamic forces required !o

produce failure were of the, same magnitude as the static. The 3-in. specimens failed at a

lower static t,:e-iil stress than the 1-in. specimens. The dynamic stress values showed

about thv sanie s'ate r its the static values and fluctuated essentially within the extremes

of the latter.

Pip, tr,-,s,.- due to initial drops art, given in Figure 6. and the maximum values at-

tained are phlottld in Figurt, 7. An examination of Table -2 and Figures 5 through 7 lead to

he following observations:

1. The influence of a large number of repeated loads on joint strength decreases as the

p)rer('nta•.g of bond is i-'.reasod. For example. Joint 1-1. wit*, 20 percent bond. withstood

10 drops at pip(- stresses of about 10.000) psi and then 1S dr-ops at about 3"2.000 p.-i. F Lilure

occurred as ma result. of the 291..1h dr'op at. -t pipe .tress of only 12,000 psi. On the other hand.

,Joint 1-116, with S:2 percent bond. underwent 50 drops ai pipe stresses which graduaill% in-

creased from about 22,00() to about :17.00)0 psi. The drop height was increased for the 5M-C

drop, resulting in joint. failure, at. ma pipe stress of about 56,000 psi. Thus. a joint with )20

percent hond failed after 29. drops whereas a joint with S'2 percent bond apparently remained

tmndaniaged after 50 drops ott greater forces.

.!. In soatu' cases'. taln't. is it di''r.'n:i' in lin lt-% II,%i;iddnn~'I~''UIrrrl.

SUVOi'sIS t' I- idnt inid driiiis, v% hidening. vior~~4'Itt lion tilitri' in i li, jointf. Ti-nr-i' - an

int-reast, in 01 k'r vasos. i ndicaiiing !trani ii ~rdi'nn!g ElIofhit (inifit inliv %i'ry uImeri 'i) Ijilit., li

.Iuoin(I *1-3 ror 'vntplIv. the' jpipt stress ll4.i'ri'ilwE' frrin abiout Is.0 to(I) nlaoni 91)(0) )-i 'luInt-iithe 1ns -in. dlroips ulwminrsi in tiuunt 1-202. fl~ive' k~ an ileiniii'In e,I firs an r'a. frontr islpt,'i

-400 to~u flionhou :01i)otO psi ilnring finir d*i.uroii.

3~. A rouinghly I inintr rhin'ihii lshilI oi'.vi,',' Iplit'wi' Iii' nppir Iniumd of t.'is-ile -afi-- in ihi.

pijis' and 111t.' li'r4'ilt--11't' oil' 114111(f.

I . I i t -I Ii' M raighi Ilin' ritI to hI Ilist o f i , 'l htonv I it zz ignre :i i r To wgil It I,, l it A I lit rou'sdt

tht' Maiin. 'liii 1iun1too 'nnin prudmh~ly rosuii from 1114 (Ia imQ51011 in Hit hi'lond pc-rf--i~rurt -d

torwrilnaiIon of ilip Wasz-. wr il in thn' infl-o ring groovi'. ~i Ili ho 'xn'rri;' #'nitl of' ti'' piqw. rnd

i tIhe fi Hoit at In hejunit- art, or pipi' anhd could ing: sa'' Figilri' "..

Tilt,' -wollo~tr ariu'n' nih' jpointl in ligur's A. H;. am! 7 in"1 prodiilsI 1wi e.npIlunid a.-

fl.I I i'r !Il5off Otit- iii liUI Uic)It'ii A'tt vminw ist IIihv±! j'luvsjit " ut I &'-iunr :si-i - j'in i

-2. Po-- Ii I i' Naria I ion ini joint of an I lit aond i'rnro It in ':-aItrvi'ne4' (Pt pvir('i-ntao' 'iof I'e if lI.

hi may\ Ibv soi'( inl Talii I that agr'otii't ne t bi-MV'a Vistitil and uhIr:,soni' oir'.I:fi boii ud

k wii ho(' Iv 11'ttqr tnhie !.-'cund serio'' of spi''inni'iis than foir ! !.( firsi4. It %%oiuld appeiar I liai!

td:rasoniv airt:ih isn' improving and 'or t hat highi'r ho(nd( pA-i*4n'4ft:1ifi': (o%#'n I;ht) tirv'.ut'

1. Errors (if ila:i n'iluc't ion. No gn':kt'r 11hli.1h1 i ol' tt114'1 3.

It ii:U% boi noefid diut Ilho !t.! rc. 1n- nit h1.1%v1(11 heilo pr'so'nie'd in1 ivter;- of .- 'rs±.' va'r

-I ro'-ss in tIlE-iiv :ir-iwauzw'i Joint. 'fbi ave'nug sho':m sire'ss van hpi vlihsina'1lvcA 11 d~idn hA

:iri.:itirod ofam: loaid actin 1flZ IJ a1 joint by> its boindl :ts';. A pulo1st or)1( ho hi'4ar -mire- =% ''n-it

po4r('4'nt licinll wou~ldi 1)p)4'Ir i41 shioiv tha Iliii' s'hear stni'ss wvhich I zini U can i'ndsire' sh'crt':s-k

A %ith i ncrne'ing jpi'ncEnt liond nuthi than W 111 inig *'t initI~ at tfiiltint. fon Nht snaiM! anmi dv-

naircj( loadingz. 'filni tfi h !,i'Est ilpiirliani ntiat ion-iii'ii. nasn-i'I. (fltu the load wvhiih a1 jointi

(-;n !ieapport inc(rease~is %vith pt-rcns'nt biond. Wi;'lit, di.-tunls't.

IMPACT AND REBOUND VELOCITIES

'v rier inii ml v psllisi eon ttii a the ' i neavi pl ait '. t lhe dro ve i e'st v de'tbee re 'eanlm m im se 'vi-r~i

i l~v imitguitui ie- of its re'boucnd v'i-ovie Iit)Ic he' iep to ilooa Imutli pi'r.e'rnt o~r iiii.'Ifi iifisI iimpli('t

~ eieu a hs.Ihi'rt'reors' ht'v iangniiiitie' or' thi. ' i totd Iising.it, vifim. o''IflVer i iii'v-w o we' i tsI q)S, v.i

11h4511 i . t i 1 t tiniv oat or Itht iii it til i uipjlit' ve'loeuiiy. R'reentt VPvidum. it* ~r drtip hitight ,

Wi d alssoe'into id re'ouintnd ve'Iewi iies or the' vi'hiv e' art' gjie'-n in Vi gtru' K. 'I'I-se'' cthou i ndi "cit'

111:1t t h. totali vs'Ioevi t v cdiii gi' vacried rrenat up tos adiuit 2.5f ito it micx a stit efo stlsos :,.: rF'*4 w ho'ru.:1-4 tics dropl %t'Iii'iiitiv raingted from Itiotil 1 .1; to1 about m~ rps. who the' Idtiflf' v'iet'jt '*x-

vo'e'is'41 aboetut it 'pis. tisi rol'hendtuelo t wit grt'ni.i% re'dltivedei. 'This phi'-noeirenoi pirobablyrosii ced fromthti i comorin oer 11 r ticS! or t he kine't ic enh'rgy (ir the' drop v''hivel into plivatLiv

stIraien o'ne'rgy in the' tinpactc ilsite' cend th'v ve'IhvIi'.

F"or jopints cim i nj Iv; than 6t) pe'rve'na bond. Iilit' maximu ucim ecpci' i %''koid a, snd ch~atiL"'

iii t' hci'It*v re'qucirode 11) produelees Iiionnti i taire' wi'ti' abhoiut 10 iandl If; fpjc" r. 'Mpie'eti vei . I'l u - all

hi-ios rait tre's wi're vaiasw 'Iy isv '.1' en no t' I) sign tri ('i ftly Ure'tiit t han the ecatpivity or high

imact~i' shock. lnavichnoý.

For joi n ts hiv inu m o re' t htan ti perre'n t bond. the maximr iticiinmuei 'loit aindi hange'nc '% c'oiity rv'cpire'eI ror ionel failure' ý%i'ri about :1,1 aned 331 fps. re's;p'c'ti~ e'Iy.

PLASTIC STRAIN ENERGY IN PIPE

T11.'hte' sce t ' raian emflrg:; alsorlie'el hr the ptIi' pi'r unlit voltimi- wais obctained flS (01-

low: Iirs. n'.acar'elknateniv plastic -tre'ss-strui aflIzta we're ceompared with :'.taitic data(Fl cure' lto) fors tic. pipe' and! rotund to agree' fatirly we'll. Ne'xi . the' eIsi part or' the area

uindelr th I ;ta's stiv sm are'ss'traiin curve' (orr-simlx~ i ng ito c part iculocr dynamin' load! wai.4 compur.'d.

This uer'ea rep)r's ('it e' the' pilast ic unit st raiin e'ne'rgy for the' Ii( and wa.. p!' tted agzai n t'r-

coenI age or biond in, Figtcre' 1) tocge'ther wit i simtilarly ohtccine'd ene'rgy front static' tf.!4ts.2 Ex

aIn int ido or Figure' 1) eli slose's t he rcI ol'ouing

1. l'or bionel pe'rce'nt agi- hIc'te'n 60I aind %0. t he e'nergy per unit volutme appears to Le. in-

tii'lie'Cji-'ft, or pe'rce'nt ionel.

2!. Foer a give'n ucnit vne'rgy. a1 st ut ivat ly lo-'tieui joinrt with otn ly asout 4.a pvrvde'tt boned~a

eiejec'va le'ri to it dynamicit'aIly te'sted joint wit ab nout 70 p'tervflt hond.

:1. TIhe' 3-in. p p' tcr' vapauelsIe'if crihc)ew iping far Ie'ss p1 cst it uanit e' argy. genercally. t han

The flexibility relationship., of Tables 5~ anti 6 have Iwen included to indicate which

"part" of a given spoc-imen tends to ar'sorb the most elastic strain energy, this absorption

being directly proportional Uo flexibility. Since the coupling flexibility remains constant and

the joint flexibility varies but little for a given pipe diameter, thie proport~ion or the t'gLal Plas-

tic strain energy Absorbed by the pipe is primarily a function of its length.

a~t; in these tests, the pipe-. undor''ent at great deni nf axial plastic deformation. t4hy,

then. is the elastic flexibility of interest? The answer is that the initial (elastic) deforma-tion of the pipe determined the subsequenit course of e'vents - t-he highly ductile pipe nmerely

continued it) deform plasticrally after yielding had begun. attracting to itself the major part

of the energý imparted to the specimen.

A reduction in length of the pipe sections led, as~ may he seen in Table 6, to an in-

crease in (he relative flexibilities or th~e couplings and the joints. That this change, in turn.

caused the joint to absorb a greater proportion of the total energy is indicated hy the inahil-

ity of the shorter sýpecimens to sur%-ive repeated loading. Throw A^ four specimens which

failed as a result of one drop were short specimens-. ranging in length from 20 to 60 percent

of that of the usual specimens: see Table -) andi Figure 6.In gesneral, the flexibility of the joint relative to the total flexibility of the 3I-mi. speci.

:nens waý: hetween about -2 and :3 times greater than that of the I-iii. specimens. Therefore.

;-night be argued that the :1-in. joint absorbs a greater proportion of the total strain energy

a-.ailable to the specimen than doe-s the 1-in, joint. The relatively low %alues of energy

absorbed by the :3.in. pipes tip to faiilure of the joint (Figure 9) may be interpreted to support

this contention.

From the preetf-dii'g discussion of plastic strain energy. the following observations

can be made:

1. In an acceptable joint' (one having at least 60 percent bond). there is no increase in

resistance to repeated loading with an increase in bond percentage.

2. Repeated static loads appear to be less injurious than repeated dynamic loads.

3. Repeated loads appear to be mpore injurious to 3-in, than to I-in, joints.

4. In a shipboard pipe system, the ductile pipe serves as an energy absorber, deforming

(plastically when shock input is sufficienitly great) without bring damaged. The greater the

pip.- length between a fitting and the imiposed shock motion. the smaller is the probabilityof joint failure.

8

POSSIBLE EFFECTS OF BENDING AND INTERNAL PRESSURE

In a shipboarl pipe installation, both bending and internal pressure can be presenL U)-

gether with axial tensile dynamic loading. In a long span of p~pe subjected to bonding, pipe

;it id weuld preve~t significant bond shear str.,sses from developing in joint% in the span.However, large joint shear stresses might be encoun.pMaed in short spans suhjected to bending,

;. changes of direct ion (at elhows, tees, crosses, etc.), and at points where fittings are sub-

jected to impact. The tests described in this report were tensile, not bending. But Ainceshear stress in the joint can be produced equally well by either tensile or hending loads, it

is believed that the tests were realistic. Internal pressure, which was not pre. ..,. in these

tests, would cause circumferential tensile stress (25 and 39 per(cent of minimun. required

yield strength in the I- and 3-in. pipes, respectively, for the design pressure of 700 psi) and

axial tensile stress about half as great in the pipe. The net result might be to decrease the

dynamic load required for joint failure.

In the case of explosion attack against a ship it can be argued that internal pressure

is relatively uniiil•lrtant in failures of %alves and hull fittings, and that the important factoris the mechanical s hock associated with the motions of the hull as induced by the explosion

shock wave. It appears likely that the same conclusion would apply to the pipe couplings

discussed in this report. iIence, a mechanical test without superimposed internal pressure

should serve as a good index of joint strength.

CONCLUSIONS

The folowing conclusions for silver-brazed pipe and fittitg connections ara based on

data from dostrurti~e dynamic tensile tests or copper-nickel pipe 3 and bronze coupling

specimens. 4, 5

1. Joint failure always occurs in the bond.

2. The dynamic strength of a silver-brnzed joint is:

a. Considerably less than its static strength when bond percentage is less than60.

b. On a par with its static strength when bond percentage is greater than 60.

3. When the bond percentage is greater than about 60, cracking of the fitting can accom-

pany the bone. failure.

4. Cast beonze fittings have undesirable design features, namely, abrupt changes in sec-tional area and sharp reentrant corners which probably reduce joint strength. These defi-

ciencies could be remedied.

9i

a.~ ~ ~~k .lli i.die asl ated%%i il i fiiilureý; of join(.ý ham io~ jig lv.- I han GO1 pierceni bond , re:

nI. Ilofltl filiiiures oceur al %v'lotii% ti-II.Igis lviil(, titiii t hie range' (iapaiiii of hig'h

lb. Permanent axial pip strains of up to altout :1 lir-vl ait iIoiliifl\ bondl failure'..Permainent s Ira ins in tit(- fitting aire ne'glig i ble

4%. Failure results front shear siress in tithe bond.

6;. For bond pervonilages alliot v ; 0. joint failIutri'4 are assoviati'i -dit I the lol Io~ I m im

aI. \ehcit\ hne as~ grea as 313 fps are required to pirorluve liond failuire.

It. Bond failure's are atccotpattiodi by\ pe'rmanent axial iiensilo strains in t he pipiv(if III) to abiout III percent andl permanent ircumifi'rint iii tensile' strai ns in the fitting,

of u p to aibout :3 Ittvnt

7. D-qponding priniarilY oil the ruagnit ude (ot tiii dy'nanlii load. (he t'oIlo\%i ng ty\pos of

failure'. lis~ted( in orde'r ofI tlecri'at'4tn matgnitud'' ofi dlnaitic load. can Ite e\pecteol:

:k. 1111 bond faik immedI~'(iati'l. as at resuilt of' the fir-i loal.

1). The, bond fail ,s suddenk~. after ha% ing survi~v ('I i~eral dynamic ltk.or graql-

~.The pipe, \06;+ 1 is \vr\ (lull Ii. i - capab~leh of al~sorlbinur a largi' q1antity\ of plasýtic

-trailn verizr . I iereilw prtectl'ing the joint from~ failure.

RECOOMENDATIONS

1. The, ctirrent pr't ci'-, oft ni'jotinLg joints with less than 601 pvrc,'nt hond ` )uldl tit

2. S5 ince' thie till' oif t1-t describoid iii thiQ repor is effectivi, in ev aluat ing the d'v n amic

strf-mgih of a brziami joint. it is suggi stied that its use he considloreml fro te~sting other types

,pt pioe (tonnltions su~chlu ii .Al~ed joints.

3, rbet( gi'onlltri' fit-sign ileficioncies of vast bronim, fittitngs shouldl be ovi.rcotte. .Atj

alte-rt!ial vi. couplhing &esign lim ing roiundied ri'ettrant corners and grad~uallI changing see'

Hitilil are'a is shown tit inIig'iri 11. Tho clmnifgi's propotsed( in Figure I1I arv oquaitlly. appli

vahili. to fill simiilair cast fittings. 5

10I

End of Pipe Flafed Out

-Washei

Relainvip, Flange

A. A-

0' Tapece

S lit Plog Cap Sulev, QuIco Release "Iechanisr

plitUdge Ring Pipe

Section A-A A_ZY z ZZ-Az

NO I

AT,; A Test Vetuciv

Enas of C la, ,edPipes 6%ithii Flanges

See Section A-ASi Ivet-Btaiec

JointCcu;lIng

owl'Otcp Test

F lange000r,

Acce iet, -eier

Suspended

__j

Impact PIlle

Figurv i %kwttion or D-p Tvs( V -hivit,

11

E CABLES

REL ASE

Ec NISM

4mob r.UIDF-,) ~ Wow

rROP TEST VEHICLE

3-IN CH ýT r F L :MPP CT PLATE PAD .11., i U.

Figure -2 - Drop Toia Vehicle Ready for Relonse

3 ttIj 1IIj I

Jo~lt

Figure I1 - Failed 3.Inch S1pecimenjoint Numbers 3-101 and 3-102 were cowed Iosetwtudinsity.

G Necking down of pipe

$ )Flaring ou~t of coupling mouth

3 Ctackina, of coupling at reentrant corner of shoulder

G Abrupt change in cross section at Juncture ofpipe and coupling

0 Complete bond failure6 Incomplete bead failure

7 9xts bond ame - fillet

8 Kutts bead ware in bess. mesta reeve

Zaires bead ares at ed of pipe

13

SPECIMEN 1-7 AND 1-8. DROP No. $12.5 INj

fr. w

d9 8 fy

IL 6 USIC

Finury 4 - Typical Record of Tenuuile %MI~issAeerL~ and Blosdion stwaim

so

70 YNA MIC TESTS STATIC TESTS IREF 21...

* List OROP I NC14 PIP( 0 EINCI PIP!:

- Asr 0000 3 :%c .)ipf 0 3 11WCV PIPta6 1. 64

Sso____

-~000

5 0

40Or .10.% 140".0 WacLOOVS

.0 II0 '0 30 ~~ 30 4 0 6 0 S

to 34 uciw so ?.s

Vigurtp -IP Pasta attII B1Iond F'ailure

wid1 'vmvrt o l~eft of. dsymIlI "c &s vS bringv the.ama s C tluett . ag ~6*. 11ab thu the. #WMa ofMH 01-10kWWA IPA*8 4 WO

J. The Illot. "C" "WOv 61 am 4as la4. 'Phr tW. "allaluIme am. :.b Wat"sm bsamm vigwes It 1ktheah.

ga ifylRO -RI-1ILftI icf oi8~ FIST~ D4P-AILV~t I HCIPI

FIRST coop -FAILUPI I mcm P191

It

140-

al

Figeve # - Pipe *tsi dwinni lasitil DrvS.. IN. We. "Passm veue Ukiah e@e*hd be&r.n urnvet keq.. eW" OW. m1"

Auft"W we" s... ebout hew. he. IeeN. *4mbb iske s kews belo .em.

IIe..pwea" 4w-s em Is, -Qpwmeftoa sein Ve. I *MOOi t.

704I *co Po

I IN1C" Pot 44

--- - *~W'6%

'a .4S0'- pa ts' *Wl

140 - -o

I~~Te 'C 6 0.=110 otme 4"s a~IGOm

0i son~~4 ~ibW Iloome ofute. Ag aubs

Vruev? 7 %waimem %sit*e Of P~ipe *Weds

Not- . it& **&&A 6w~5 ho. *"e Awteteb.

W *4e We at 0,~S "***1"aSW at IWW am 44W

to~. m at .. u Wsa.. be& am" & ame M ao "d ofmom ON*"i of 60 600&.

4. TM. meiN~ we*" ban on. to@... Ofomo eYejmaw* rOeI 1.

IT

** * 40 Gewe in. '5 0 ~

¶1III!.

Jizztz - - -r64

IT - - -

*-------* - 1* -s so fa -

ow oftemo -- -ts

ý'ef-%-N*6W "u Itru itit)o fir rtri

4000 N~~ O T ral

3600 -

MOO -4---1 rs 4

gscgpr Pon opg

~ Pools? AS .OIDO

lace

*at "M

-se 4- so

-pwv. pw Uo4- %04m.-- IPIWa wmF~w

o FRMo 5STIC TEST OF CO-00 POIE

INAO IPIKAVIED DYNAUC LOAM#Q 09 Cv-& POPE 0r

40-

50111>U',

or - iL

ritwo i0 - *4Bft ~.9a ma #w Cwppie.%rk.4 rn. osn *eat4ow n% Isiuasaw teats

A bealal C

LA -T

1i'm coupling per Ref

Radius 30 percent of T-

-WSocPl Depll,?M -N 044' 1a,00

0.06"

Sholde r~dt S ,, ~ ad.~ 3.06" ,-Remove Material60% SAn auxiliary tirdzittg metal

07 insert ring could be used5 percent of N is peirmit'ea by ptesent Spec, tar here for extra stlength.tarlit in brae rietalmser' ring gfoo o.ReviseSpec to reQuire tadi, - 6iJ percent ot d 0 03"in this case i Results of Changes

Detail C I Increase in weight of coupling"I--- 2 lnciease in maximum dixinetei of cou,ýIhng 'b,,

ScaleO?' 10"-

Fig ure 11 - Proposed Coupling Design Changes

A I-in. coupling hen been chosen for puarposes of illustration.

The changes are applicable to ntht', similat fittings, Vit., elbows,crosses, and tens.

201

"f..BBLE I

Dimensions and .rears of Pipe and CouplingsPipeI

Outside Thickness Coupling Socket Diametei GrooveOut-i-e- I LandDiameter Pipe CouplinE Bore Length Outside j Inside Width Diameter Width

Size (max) (min) (min) (iinf I (min)De T Tc Bc Us ls 0 M G N

in. in. in. in. in. in. in. in. in. in. in.

i 1.315 0.095 0.20 1.108 2.38 1.72 1.315 0.154 1.424 0.130

3 3.500 0.165 0.35 3.18 8 4.20 3.500 0.287 3.613 0 55

Dimensions of Pipe* aid Couplings"

T Pipe Coupling 100 PercentSectional Barrel Bond Surface Ap:AC:B'

Area Sectional Area AreaSize Ap Ac 8"in. sq in. sq in. sq in.

___I_1 0.36 0.82 1.27 1:2.3:3.5

3 1.13 3.88 6.31 1:2.2:3.6

Areas of Pipe and Couplings

Lc

Groove for Braze Metal Insert

T _ A P = nTp (D - P

S. - -- ... ,•B• Ac= T c(B+c

B'= 2nwMD Total AreaAvailable for Bond

Pie Coupling-- M.__,

(in section)--, ,- --

*Dimensions are from Reference 3.

$*Dimensions are from Reference 5.

22

_ ' .5 . '54 ,55 . . 5 **5 ' .*5 5 : 4*.* + ,.. .. 5. . . .. .

,________ ______ ,5. - ...- ~..... .... . ............ -....... ..... ...... .... ;'' ., . .[ . ;, .

,--.. . .. . . . . . . . ... ..... o . . .. .. ...... , ._•.... . ..

" .:.. .. ..

__ __ _ __ _ __ _ __ _ _ _ __ _

I -

"- - - I -- __

6Z55 I

__ + - -• _ _:_ -. .. >-W .. .... 2 . ... . ...

. I I

I '! ! - -

.. , ,+

5__ , . .._.. . ... . .

__ - • - j • • +. -. -. . . -. . . . • -+ M +

-.7 , -. •" • -. : .- .a a- fl -

S..... -. . .. .. L.4..4.'..... ,

- i I

S.. ... . . . . . . . ... _ • #. ,- • -, •'

.

* . i. ,.

I_ - i " - - --.

'•• 'I--* -- -."____!?•: • •. .' -- - T Z: z 1

i . ! . . . .

__ __ -. __ I .-. ... ,.. .. .

- ...... . a . ,'-.a,, +-"7. ..a . I

____ ... I _____.:+

I-..... . . . ..... o. -

-.. . .-. I

"", ,- -

, . . . .

• : . •._,_ " j7.-. .. 'w>. '.. --"

K. .. 25 . ,• ;

+- ..... . ..+ i. .. .. - I-H--- I

§1117i .+ a . Ki +:~ +++ 1i::

-... .. .. .. .- :...• ,... .I,.7 _I -,- . _-_Y

TABLE 3Pi pe Loads tit Bond Failure' - Static Test Data*

-lnch Pipe 3 Inth Pipe

Pc rilnt liIIhmale Ijllhtate Peifenl Ulhi'iicA f UIt,mateBond I ensile 1eiis, Bond lensiic TensleC

Iltll rUML I ulrce Slim% .| l sra ncsn( F cIce She•sInspectn i n Ins ,tifli on,,, n p

kip kill n, , kil l kip n"

25 5'm £1. 4

Ii 5'I

'4 b, 19.'

.7 1 .54,5 43.

4E..

4. ,5 4 E. 4

n i

h; 2.. S+.. 4+ +7.: l h.7

I

44.

I. t 1.<

* I

. 4 T •IE4 , "

* I

0s:,,fl,' , 1',..'

IiS:• 1 .. !.' il I. . ..i I,, I " , ,.. I . . .

/ /

II- -

L ull ' _ _ ,* .I

Flexibiitides of "Partsr" or Sp('ciniens

Characteristic Pipe Size Pipe Coupling Barrel ,iJ on I

Length Ll Clear Length of Lit Length of Coup- I., Depth of SocketPipe Section ling Barrel I 2M N

0See Table I ee Table 1,1i.4.5f, in. 1.94 in. 0.44 in.

2~n .5u Irl. 1.94 in. 0.44 in.1i.0 1.94 on. 0.44 in.3,.3.16 in. 2.31, ýn. f 0.83 in.

Are,, At Sectional Area of All Sectional Area of A, Sectional Area ofPipe Coupling Bartel Srnc(et -in.,

ISee Table 1, (Se Table I I See Twoe I

I.n. 0.36 in.2 ').82 In.-, 0.73 in..,3.! n. 1. 73 in.' 3.88 in.*' 3.61 In.'

B Surface Area of BoricSee Table I Por.cent Bond . !( Pet-

cent Bome III

Elastic Modulus Tensile ModLIUS El Tensile Mudulus G Shear Modulus of B:"e,MinimrumI ASU1'd

lb lb

in- in, in?

Flexibility F1 Piot Flexibilify Fit Fle~libility -1 F1 joint Flleibi intCoupling Bartel A~croxr-alte

E A All E A . EA -GO

-*n. 1.5 n 0.182 110 1 1 0.11 ,

in i

0.63 -10 7b-j 0.187 - IQ- lbd

G. is? - 10-i. -

Cleat Coupling Couplinrg 3lckteLength BarlPortion of Ppeo Inl Socketof oPJ;p

'ii i'Pope Clamped within Fla ngec

atl Eseb End ofSWI berL,2LKi LiL'This alptuoimatle lispiesseal isclrides thM effects at pope samd Writ metal itiitioded within Socket

OW4 lilould not be consiOtbed validl let oflllallo of percentl hoed below Sheet S.

25

L00 In CD1 -ý

- In

~'- C m .-. '- -~ cc .~ u~ al 2-JV, C, . le neCD " ý "' CD c:: 10 m = 6 C=; 6'. C=;j V- - C

66I - "

5.r 10~ C, U) - c, 1 CV. ' o) to

Vfl en ~ V'. Ub 'CV ') .v IV!.V~-a

ACKNOWLEDGMENTS

The' writer wishcem io i-xpn'ssm his gralijicade 14) Mr. U. I,. Wilcox, Piping (Cotodinatoe.

Mlare' Island Braz.ing roj.'t cr sup~plying ihe' ie't .4pevimemn~ anti publicati ons, anti data

from (he. Brazing Projcwt-.

This projectI w1:4 con(Piek'dl and iniicitesel in t he. Shcwk Branch. Damid Tayx' %r kmode.Bt,. in. li, %fissr-4. H. IE. Cmaa~orsc* andi If. L. Rich, to whomrn, andi to Mer. H. IL. Bort, the writc'ri-t ande'hift' rer directiion. advivee. and 4erilvicjsin.

Thiknk.s are also dlue' it) l's If. P. Ilashmull. (s. Junkin 11, K. P. Shorrow, and

P. ) a'naIl for. pe'rrorncing tc'sis. redcucing deucet, andi assist ing in the~ pri'paration of thi- re-port.

REFERENCES

1. ''ihclriv'ittien, Sil~i'r B~razing. santi Inspctc ion of Piping Systemns." N.AVS'HIPS Re..-

port ,!.t)0-03 1-1; (lNTERM~) (Ouet 19631).

-2. Kurku. J.. "$ilk'r Brazing Preeji-vi Progre'sm Re~port." M~an- I-land Xa~al Shipyard

Report -260A-27-63t (Ouet 1963).

:1. MIilitary s"peceification. Tube'. 70-30 sand 90-10) (oppe~r-Nitkel Alloy%, SearmIes.* and

4. Mlilitary Spe'c iificaflo. Ilrenze.. Vmk'e*: Castting.s. MI11..1654 1A(0op). (.Iay 1961).

51. Fiuing.. 11ront~o. Sil~.cr Brazing Alloy. for W~ate~r, Oil. andc (ims. BuShipm Drawing5tN. 5 ~ :t ~7Ii.He' ision 1I. shte... I (Jan 1955).

6. ~tal~s~v pecification. Braying *AllovF"..Sile'r. MtL-B1-15.195 %(Ships). (%IA, 1593,.

7. 'cu--iim. J.J.. -- sal.. *'Teots oft sil~er Brased Joint.s," Repeiort to MAre' 1celand NatalShipyard by Westinghous'e- Fle4-trite Corpration, Prepantel under Conmtraet T %.2l69OX

(FB%I) (Der 196:3).

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Copies

16 CHBUSHIPS3 Tech Lib (Code 210L)I Lab Mgt Div (Code 320)1 Stiuc, Ship Protet, Hu1! Molls & Fab Soc

(Code 341A)3 Ship Pmlec Div (Code 423)i Mack Arit & Powet Pipig Sec (Code 434)1 Sub It (Code 525)I Malls Dew £ AppI Si (Code 634b)2 Marh Atilt I Piping Sys IS (Code 643)1 Navy Indus Fac & PvC Equip Div

(Code 770)Nuclear Propul JCode 1500)

I COMSUIPAC

I CONSUILANT

I DEPCOMSUSLLANT

k USNMEL.

I NAVSHIPY0 CASFN

3 hAVSHIPYD MAR[ (Cede 260A

I NAVWrmY0 %lORVh

I NAVW'L;'Y 0 PEARL

t NAV.r4IY 0 $FRANI

I NAV'ý11,YL P T W.'

I .UPSIP CAMDEN

I SUPS1IP GROTON

SSUPSN:P 4PTNWS

I SUPSIFP PASCAGOULA

n CON, DOC

UNCLASSIFIED-Security Classification

DOCUMENT CONTROL DATA.- R&D(Security classification of title. Il* at aae ydM~b at ~.~t b~ee entered who"1 Usooverall report I& Classified)

IORIGINAITING ACTIVI!Y (Co.povatsa a~i.o,) t.. REPORT SECURITY C LASSIOPICATION

F partent at the Navy'David Taylor Model Basin, Washington, D.C'. 26GRU

3 REPOK* TITLE

STRENUTii or SIL VE11 BRA ZE D mpFr .Jo1Nrs IJNDIKI DYNAMIC LOADA

4 OtSCOIFFTIvE NovaEs (Type of report an'd IUndusiv, date&)

Final5 AUTNOR(S) 'Lost ,inam. first name. WIlal)

Zilliavus. Stephen

6 RPOT AT V. OTAL NO. OF PAGES 76. NO. ON, Ref's

£ EPROA A .pril ow?, -29p.T

S8 CON4TRACT 001 GRA04y N.o qa. Oa16106aOa REPORT 9NUISeR(s)

b PPR049CI No '"F01i:1 10 01 1

e Tas :3t7LI f9s. rm=PoftT mOeS) (An otherA. number* ahzi .a.a be assign-

tQ AV AIL ABILITY LIMITATION 4OTICES

Qualifiedi reqUosters miay attain copies of this rrport from DDC.

17 SUPPLEME-4TARY P401ES f12. SPONSORING MILITARY ACTIVITY

Departnment or the NavyIBureau of Ships, Wn'shingion. D.C.

t) ABSTRACT

De.struetiko ik nnnmitc load tests weret eo-(lurtef on specimiens of coppor-nick-el pipe joinled tohroflze copinsv (; radle 11 silver-brazei alloy lx~nds. The bond areas varied from 9) to S5 percentof the total --urtaces available for bonding.

E:very failure otccurred in the bond. Cra~cking of the coupling sonmetitmes accompanied haond tail-UrP. In no c'ase %%as there rupture of the pipe. Since nmany joint failurt- apparently were intluenevhy~ a coupling geomnetry with abrupt changes in cross section. a noixiii'v- coupling deosign isProjposetd.

The dynamic forces reqjuired to produce' failure' ot silver-brnzed joints having less than 10 per-vent hand '%ore considerably smaller than st1atu' failure loads in tests condiuctedl elsewhere on sinii lar specimen-. For joints with more' than about 60 percent boed. the dynamnic force' valuos were athe sap*-' magnitude as the static loads.

.Joints having more' than 60) percent bond taile-d only after considerable elongation of thle pipe.For suttic' ildy great initial dynamir- force, joint failure- oreurred immedliatelvy: otherwise tmu ormnore loadings were reqluiredl. inipac' ocittes si:CSOollatedi with joint failures ranged frotm alxou1.6 to about 311 fps.

It appearsý that the c'urrent jractice ot rejecting joints having less than 60) percent bond is justi-tiedl tar dynamnic loading.

D D JAN-' 1473 UNCLASSIFIED'MRCLOStJRE 1) .. Security Classification

UNCLASSIFIED

1. Secutity Classification LINK A LINK 9 ~ gKEY WORDS --

______________________________________ ROLE *I ROLE INY R11L6 *1

I11ronzit, Coupling 'rensie It' t,-;sI

CoprNickel P ipt,JointDrop Tos.tDuctil ii~Dyn amitic Lo adlPvreent Bond

Shovk Loading

Silvt'r-Brazed .Joint~sSltatic LoadStrengt h

INSTRUCTIONS

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>.A:f:. 1) age 2 UNCLASSIFIEDSecurity Classification

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