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x, y, z and M are given in table 2.Using the above equationsI X, =82,248,320 - (19.50 + 0.07 ) x 49,415=82,248,320 - 18,790,300=63,458,020= 13,688lb - inslug - ft(x 0.2157 x 10aI Y" = 227,468,820 - (4.8 + 19.50) x 49,415= 227,468,820 - 19,928,580= 207,540,240= 44,766lbs - inslug - ftzI z o = 251,440,780 - (4.8 + 0.07) x 49,415= 251,440,780 - 1,138,760= 250,302,020=53,990lbs - inslug - ft9w-4E-4OW.k4.LCzCJU4I0.-w.m.coa)qW0-4(n(AC4CLmcoOr0NLAvi17Ch-WC0mMl17;NCN0NNLAw0*1.00*Ha.NIT'04T-4qN-4W0w40co0N0'q.l0DIm0(nW0V(D0AC10*wva%r-i-4..*rLAN*.MCANento0.ClCl mco'Tr,en:o-w1:cN%QNLAtr:N(CKlNLaCIm14a%-(nCtn.030coimHCLNLALAr-iq.NNMLLA030 (DMxw.M P-4CLNtoN4N-0-ZN-4 (0al0r-I.0co03co0400'0wI*LAo3 Nco444* HC40l40LfN10(M000-4 %rNc4-cL(n (n(N40-4-40001aI4cnc40a0NCL1.0W003W0m0-400N.-0000NNz-0xC)*..e.03c00c4-4C4-ClC.vQJN aNClr,'I.4LA0n0Cml0oC10w30toN4000D0000LClw,CtNH4hNNa%Cl4LT0D%4--l~-0C1WCl0E4C"C1v .nNNq'toNNtovVNNNAW.ICN0cn0CA00CltoClC%~ ~L0(00cl)4*4ClN4.LIWML.NN,-f0o~two.co~4;~4CqHI-4co0N000NN1-4VCl0V,W00mlN0LA0L~40NNNND0aC0coCLN0ClHl-III~ :!E-4co1TITLEi RACE RING SUPPORT AND BASE PLATES LAYOUTDRAWN BYs0.
LACAPDATE- 15NOV 88SCALE% 1/16NOES01.00THICKICKTFG1.5.TRITCK.7111ITRcrw1"It11Itti~~~ILti~--------IIwIIFIG 2TURRET GEOMETRY12IC-i-0cI-L.4:0QwCD<CamC)< -0C)[n-iFIG3TURRET GEOMETRY13<02uaFIG 4±v(JRET SOL)14MODELFIGTUJRIRET15'5SOLID MODETJInITURAZTEFIG6SOLID MODEL16. .........GSOLID17'OD EAbil '.411!I.I.ITITuRRESOLP18yMODNPi N"h.'l ~ a.11 liIITTu1if.. .TQ NMIWMJ.IalSOIOEPhiIU--HIMFIGHULL SOLID MO'DEL20101'*~A 41!', it~1...........I.P~4~IIa*iRA~,~j.1:~!~pIntl %t~rIt at; ..
I..?~t~J:~ IPr1rr*41*t~:I$p1 Iitl~IIt.I~HIIIlit21.'IG '.2SUSS:SI.ON SC'.1U) MODE.-,'N.vtvIINI12441-:T!44 4.,.. ,.*.*.i,- .,,4.... ....fi1.411'a4444.4.4,4.4.4Ti4~I..4~o4.4TJ444.':.2:.H4:'444:1 44.U4~4':44: ~*'44~~1i :4444. 44 ti 44444'4441 4442 4444. 444*4'; rtu4ti44 41444..441I!.4 4.444 ::4444. 4' .'4 4:4. 4:J44'.'t44114.4~ *4244.44'4,4.pill.444IN.I:n'l4zji'r4.,,'*4~2'f441444I:.4i44:.!t 4-414 4 y~ ~~ ~ ~ ~444.44.~ 444,~4ia44I.*I444442444.44444444.
4. 4'.~:0.~~~~~N444:.444444.44~N444.--. *..,............1,*Static Finite Element Analysis4.2A Finite Elementutilizing IntergraphThe FEM Turret Modelmodeled, and the twoCATTB chassis model.4.2.1Model for the CATTB chassis was createdRandmicas Finite Element software (IRM).was built first. Afterwards, the hull wasmodels were merged together to form theTurret McdeltThe CATTB turret is unique in its geometry, specifically inthe location of the side plates and the manner in which the gunmount interfanes with the Trunnion. To study the impact of thisnew geometry on turret behavior, it was necessary to build aFinite Element Model for the turret and analyze it under variousloading conditions.
Since a 3D solid model was available on theIntergraph CAD System, a wire frame was constructed from this 3Dmodel and transferred to the VAX Computer, after it has beentranslated to IGDS, which is the graphic base for IRM. Thiswire frame will serve as a skeleton on which the Finite ElementModel will be built.The Turret FEM model consists of 132 four-noded shellelements. Each node has six degrees of freedom, threetranslations and three rotations about the global axis x, y, andz, The thickness of the various plates forming the FEM modelThe turret is fastened to the hull by aare shown in Fig (1).To reflect this geometry inring which has 48 mounting bolts.the FEM model, the turret is assumed to be supported at 48The turret FEM model will be usednodes, as shown in Fig (18).as a prototype to study the effect of the new trunnion design incomparison with the conventional one Fig (13), As a result ofthis study, the trunnion will be reshaped Fig (16 and 17).4.2.2Turret LoadsThe following design loads are applied on the FEM Model:2G(turret's own weight)3000 lb(weight of the AutoLoader)(Gun Firing wad at -10 degree or +15375,000 lbdegree)To study tne compounding effect of this load, two loadcombinations were considered:2G (Down) + AutoLoader + Firing at -10 degree2G (Down) + AutoLoader + Firing at i5 degree23case(5)case(6)4.2.3Turret Analysis Results4.2.3.1-(turret is independent)IRM ResultsVON mise stresses (which reflect bending and shear effectsabout the ;hree major axis) are in the 70,000 PSI range, asshown in Fig (14).The vertical deformations are shown in Fig(15).Reshaping the trunnion area resulted in a more refinedmodel.
For the turret, as shown in Fig (16 & 17), VON misestresses in this refined model is 44,000 PSI and occurs aroundthe slot provided for the gun mounting block, as shown in Fig(19 & 20), this area is shown in detail in Fig (21).Maximumvertical deflection is 0.07 inch, as shown in Fig (22).Theforces in the 48 mounting bolts are tabulated in Appendix C.4.2.3.2NISA ResultsSince the CATTB Chassis FEM Model had to be made availableon the Cray Supercomputer (to conduct Dynamic stress analysis,as will be shown in section 4.4), a stress analysis for theturret was conducted using NISA software. The results are shownin Fig (23 & 24).Comparing NISA results, with IRM resultswhich is shown in Fig (19 & 20), indicates that NISA yieldshigher stresses in the top plate around hatche openings (76,000PSI vs 45,000 PSI).This is primarily due to the inheritdifference of stress and strain formulas in each code.
NISAresults are more accurate, since stress in the top plate areexpected to increase due to the reduction of the resisting area.14.2.4Turret Analysis Results (Turret as part of Chassis):It was found necessary when analyzing the hull to merge theturret and hull models and study their interaction effects(section 4.2.11).This provides the following actual stressesin the turret.4.2.4.1IRM ResultsVON mise stresses are in the range of 36,000 PSI, as shownin Fig (25 & 26)4.2.4.2NISA ResultsVON mises stresses &re in the 67,000 PSI range, as shown inFig (27).Comparison of the results (4.2.3.1) and (4.2.3.2)indicate that analyzing the turret independently from the hullyield higher stresses, because support points are considered asrigid. In contrast, when this support is considered flexible(has relative movement), it yields lower stresses. The latterare the actual results which reflect turret-hull interaction.240E4E4U25-,ilet.
I L.A.J I t .i'-:r-..c.szLU.J I~...cccjLx..-n-vrq-~..)j-.-c C t-r- L.iJ L-J..J 1j4 L-... L.L. Ic---.---FIG 14STRESS 11N GATTB (COiVENYrc'NAL26TRUNNION)r-C-N-[EEL-LL~.!LL-JLJ.A-gmLLftLLj----*-G-EELa...)L ,4JLL-EErLlQEEr=E.J.LL.JiLiG 2~. F4---j1W5C IG*-.:5.FIGDEFVL-:CTION .IN CATTB (CONVENTIONAL27TRUNNION)~4zo4meZ,pli-n14-~~W-1.128...
...X..litLA91AbIjIIQ.I'Of-VE.LS7CC3jL~IE--4OR.31Z-455It-,I:it,Ot~iPiM'!!i%it)'CH. .......3iK;'.A"HA, It "nf~ifqH'104x,k'NR5,C-5C-.jU3IjH'A4AM)AoH:4AYtOI.:33I~rA)V.t"!*~06lDuo 01'IVrf77-12A",f,En U)MWjW+w-'pj'mU r-2:mnu0)mU)0ccG'00m* 00c(cLi)cumW'ITL)coX)-ma:wcDcL00oeH0I1(n0cc 0Dz w Id Id=)EumOw ((Da00cuN'-1~JoI',NN(U03-fiiS)(UGfriCD(7(MIX)-Nrcuapirua( GJNS0D(ZtLa0a.cc0tn-Z:(i,'--4VIG 25CT-1.-Ai;C-2R.:A5n~_C f,Siliiia-r~a-rr.a...a.
ME ..............1m..~ta.a aaa...n''. ....ts.aI.. 1aaa~Na.s Iii___T.=s.___wa~r-n..~~~L~~NnnXi *P11.~p.llaaa.ftii - rI:faa~ba~a-main.4a-~l*-~~~---.ra~a.I.A~.~n"...."r~u..aaaaHilla.-j!.laatill)...-sac~aa*d4 aa4a-a'na:2.aaa'lr*1.-'.0,R.aIaaa.. lP\~-~r.a.rrIrlaa;a'a.aniA..aSdll.nCJa~trja..a a...la~~aaaraS1aaAS.lii~l~!r~fl~.x".4ir~~f~!.-a.RT s:-aalOf.a a a , FL .aa~~.rl1n.a~.!~la_Ll1ha~LLaEx W WCL'LImcWLK:Jin~I--.'......HrH0FIG 27NISA ST'ZFSS RESULTS-TOP39PLATig4.2.5Trunnion ModelPreliminary turret stress analysis indicates high stress inSince the trunnion strengththe trunnion area (44,000 PSI).will be reduced by the 8 holes (necessary to accommodate themounting bolts), a detailed stress analysis for the trunnion isFor this, a solid finite element model for the trunnionneeded.was built (Fig. 28 & 29).This model consists of 1860eight-noded solid brick elements and each node has three degreesof freedom (translation in x, y and z directions).
The trunnionwas constrained at the location of the turret casting and topplate.4.2.6Trunnion LoadIf this forceThe gun firing force is (375,000 lb).increased by dynamic load factor of 2 (To account for thetransient nature of load application), then each trunnion musttransmit 375,000 lbs to the turret casting and top plate. Thisforce is applied at the depth of the slot provided for mountingthe gun block. The gun mounting block had to be secured by 8mounting bolts to the trunnion to prevent any movement due torebound effects.
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