STRESSES IN VESSELS ON

LEG SUPPORT

NCTTATION:

ll' = \\'eighr of vesse l. lbsn = number of legs

wQ = -- Load on one lcg, lbs.

R = Radius of hrarj, inchH = Letsrarm of toad. inch.ZA,28 = Dimcnsions of wear plac5 = Strcss, pound per sq. inchr = r.Vall thickness of head, inchK = Factors. see charts

C=VAB.inchC = radius of circular wear plale, in

/h

D = t 82: \ / IRr r

t, =: [

.o, ' 1tq,

I-ONGTTUDINAL STRESS:

,, =: [ .o, * (Kr + 6 K,) +

if ,*, + 6x.)]

CI RCUTIFERENTIAL STRESS:

+ 6r{ i . : \ f rK, + 6r,r ]

lrffiES:

Pusitive values denore tensile stresses and negarive values dcnote compression.coinpu:rng the maximurn tensire strcsses, in formuias ror s, and S., K,, Kr, K, andKt rienote negative facrors and Kr. Ko, Kc and K, dcnuc posirii. f*roo.compuring the maximum compression strcsses, in formuras for s, and S,, Kr, Kz,K:, Ko, Kr, Ko, K, and K* denote negative facton.T}te marimum tensile stresses s, and s., rcspcctively, plus the rcnsile stress due tolnternal pressule shall nr:: rrceeri the allorvable rensile suess value of head material.The maximum compression stresses S, and s,, rcspcoively, plus thc tcnsilc stressdue to internal pressurc shall nu excced thc allorzble comprcssron stress value ofhcad matcrial.

al lhl

r t ' i

z^€if t --rgJl' lgj

STREIISES [Y VESStr' S ON LEG SUPX}RT

0.30

0.25rtl

Y-on

{015

0.10

005

0

I

-i--_-r_

I

02 0.10.6 03 1 0 i2 1 5

035

uiu

02 0r.06 08 10 12 15

\ALUE OF l(/ & K..

\o)c 0.25

0.15

0.'on n<.

l l

VALUE OF A-. & K6

STRESSES rr* }TSSELS O}{ LEG SL,PPORT

0.?0

r\- -u l :

f}..|

0!

0.05

002 01060.81S 12 15

D

0.60

050v,

- 0/.0-.|t

430

v.4,v

vtu

02 0.i06081fr12 1.5

VALUE OF K3 &, K?

i l l

\ALUE OF r. & KE

r05

STRESSES LrII'ESSEIJ ON LES SiJPR}Rr

EXAIITPLE CA I,fU LATI ONS

DESICN DAT.{

W = 800,000 lb. weighf of vesseln = 1, number of legs

w 800,000I = - = l(}0.000 lb. load on onc lcg

n4R = l0f] inch. r:.dius ot headH = 5 rnch. leverarm of loadlA = i0 inch, 38 = i0 inch. dimensrons of wear plater = 1.8 inch thickncss oi hcadcos :< = 0.800P = l0Ct psi. inrernal pressure

Hcad rnatenal: SA - 515-70Al!,-r*'ablc stress value: l?,500 psiJornt Effrcicncy: 0.85Yiel.J poinr 38,000 psi.F;ttors K (sce chrns);

c = \"AB = V 15 x 15 = l -s inch, , I .^^

D = t .82 : \ / I = t .s2_,: i \ / g= :o:RvrlLl . lv l_g

(i = 0.06-5, K, = f.$-1$. K-, = 0.065, K., = 0.025,Ks = 0.020. K6 0.010, Kz = 0.011, Ka = 0.0t0.

LONGITUDIITIAL STRESS:I . ) li{aximum tensile stress:

. r , =: [ .o, x (-Kr + 6K:] . l f , 'T,-Kr + bK.) ]

, , = lWlg I o.a,ro(-o.o6r : 6 x ooior * s 1@' I .8: L l00 v 1.8

(-0.065-6x0.015) I =J

The stress due ttr internal pressure:

PR 100 x 100

t =

J l - , -8 = * t77Spsi

The surrr of tensional stresscs:7.r|. i. l . 1.771{ = lr).-i l l psi

It dr;.-s not crcer'd the strcis r.alue of the cirth scanr:l1.5tXt ( 0.E: = l . l , t (? i nrr

+ 7.6i{ psr

STR"ESSES L\ VESSEIJ ON LEG SUPPORT

l. ) ltlarimum, compressional -srrcss: , ...

s, =9 [ .o, r ( -K. - 6K:) . l \41-K3 - 6K.) ]

t , =#. [ 0.800(-0.065 - 6 x 0.030).*VT

( -0.065-6x0.035 I) J =- 17,0a4 psi

The strcss due to internal pressure:PR t00 x t00

= + 2779 psi2t : x l .gThe sum of stresses:- 17,9,S1 + 2,779 = _ 14,266 psiIt does nol cxcecd the stress value of the ginh searn:17,500 x 0,95 = 14,975 psi

Circumferential stress:l.) Maximum tensile stress:

t , =: [

.o, r ( -Ks + 6KJ.: \4,-K., + u*rJ

t = # [ o.sm(-0.020 + 6 x 0.010) .. * /]00' tmvt.8

(-a.022 +6x0.0t0) ]

= * 2,849-psi

The srrcss due to intcmal prcssurc:

PR t00 x t002t I x t .B

The sum of tensile stresses:2.8.re + 2.779 = 5,62? psi

It does not exceed rhe strcss value of thc ginh scam:17.5m x 0.85 = t4.875 psi

2.1 Marimum compressional srrcss:-

t , =t [ .o, ' ( -Ks - 6KJ+i \ f , -Kz - u*, ,J

ril: lt i

; ;

:

It

STRESSES F{ tf[$Sgt$,S,il LEc .:.._!iTt }t.!

: f lJ .Unf^. t - : - - :. =* | o.8w(-0.0:o -6xo.oto)+3.\ i . l j !r : t .Br L ' t$ v r [

-0.021 - 6 x 0.0t0) J

_ _ 5.8j7psr

Thc stress r.luc tu tnternal presbure:

PP 100 x lm.:__ = + 277EFi2t 2 x ! .E

The sunr of stresscs:- 581t' + 2778 = - 3,059 psi.

' ..:':.Ir drrs nd excecd the strcss rralue of the ginh scam:t7.-s0o x 0.65 = 14,E75 psi

l at,j

. :.,i

' ' t.1:i4.1

.. ,,.'1$

i

LEG SUPPORT

SECTION A.A

I

I

VESSELDIA

VESSELHEIC}fT MAX

AIiGLESIZE

Ifiux

\t,

2'.#8',ry 3'x 3'x 318"

s'.ryJ

3',-6"4'{}' l0'ry 3.5'x 3.5'x 3/E' 6"4'-6"5',ry t4's 4'x4'x ln '

7',-t

7'5',-6"6'{r6'.-6'

t : ' - r f 5"x5'x l l2 ' Itr

7',{Y r8'-ff 6'x 6" x 5/8' t ' -0 '1',4'