/com quartz tube external pressure buckling (from STAR/al_150_long.1.txt) /com qt3= round tube, thick endcaps, axial pressure, ball ends, ev buckle p=100000 !unit force 1 bar t=.003 !tube thickness r=.0195 !tube radius, nom l=1.2 !tube length rtol=.0002 !std ovality tol. is 1/2 od tol(0.8mm)= .4mm(D)= 0.2mm(R) ltol=.0015*l !annealed/m; unannealed is 1mm/m lc=(ltol**2+l**2)/(2*ltol) par1=(r-rtol)/r ndiv_long=100 !number of longitudinal elements ndiv_circ=24 !must be even number f=3.14159*(r+0.5*t)**2*p !end force, unit load /prep7 /view,1,.5,.5,1 /pbc,all,1 /title, NEXT quartz tube (42mm OD x 3mm thk.), 20 bar, 0.4mm oval, 1.8mm bow /com buckling analysis for NEXT WLS tube, from external pressure loading /com code written for ansys 11 /com ELEMENT TYPES (nl layer shell elements) /com ET, ITYPE, Ename, KOP1, KOP2, KOP3, KOP4, KOP5, KOP6, INOPR et,1,63 !general shell 3d /com Real Set 1 al/pitch carbon composite /com layer thicknesses mp,ex,1,72.4e9 !quartz mp,prxy,1,0.17 r,1,t r,2,10*t !end cap /com COORDINATE SYSTEM DEFINITIONS csys,1 !1=cyl, z=axis /com CYLINDER BODY DEFINITION mat,1 type,1 real,1 k,1 k,2,r k,33,r,90 k,5,,,l k,6,lc-ltol,90,l/2 /com CSKP, KCN, KCS, PORIG, PXAXS, PXYPL, PAR1, PAR2 cskp,11,1,1,2,33,par1 k,3,r,90 k,4,r,180 k,44,r,270 l,2,3,ndiv_circ/2 l,3,4,ndiv_circ/2 l,4,44,ndiv_circ/2 l,44,2,ndiv_circ/2 /com l,1,5,ndiv_long,-3 /com LARC, P1, P2, PC, RAD larc,1,5,6,lc /com LESIZE, NL1, SIZE, ANGSIZ, NDIV, SPACE, KFORC, LAYER1, LAYER2, KYNDIV LESIZE,5,,,ndiv_long,-3 /com ADRAG, NL1, NL2, NL3, NL4, NL5, NL6, NLP1, NLP2, NLP3, NLP4, NLP5, NLP6 adrag,1,2,3,4,,,5 amesh,all /com LESIZE, NL1, SIZE, ANGSIZ, NDIV, SPACE, KFORC, LAYER1, LAYER2, KYNDIV l,1,2 !l11 l,1,3 !l12 l,1,4 !l13 l,1,44!114 l,5,7 l,5,8 l,5,9 l,5,10 LESIZE,all,,,0.5*ndiv_circ al,15,1,14 al,16,2,15 al,17,3,16 al,14,4,17 al,18,6,19 al,21,13,18 al,20,11,21 al,19,9,20 real,2 amesh,5,12 nrotate,all /com DK, KPOI, Lab, VALUE, VALUE2, KEXPND, Lab2, Lab3, Lab4, Lab5, Lab6 dk,1,ux,0,,,uy,uz dk,5,ux,0,,,uy /com fk,5,fz,-f !unit end load(comment out to use presure load) sfa,all,2,pres,20*p !max pressure load(comment out to use force) save /com SFA, AREA, LKEY, Lab, VALUE, VALUE2 fini /solu anty,0 /com eqslv,sparse /com pstress,on solve save fini /eof /solu antype,buckle bucopt,lanb,20 !block lanczos option extract to mode x mxpand,20,,,,yes outpr/nsol,all save solve fini /solu expass,on mxpand,20 outres,all solve save fini /eof /prep7 upgeom,.0001,,,al_150_long1,rst fini /solu ANTYPE,0 nlgeom,on pstress,on sstif,on solcontrol,on nropt,unsym,,off AUTOTS,on LNSRCH,0 NEQIT,5 PRED,0 TIME,10 DELTIME,0.5,0.05,0.5,on /GO kbc,0 SFA,all,2,PRES,1000000 OUTPR,all,none OUTRES,ALL,ALL OUTPR,STAT OUTRES,STAT /STATUS,SOLU SOLVE fini /eof /post26 STORE,NEW,all, FILE,star_ripple_pipe,rst TIMERANGE,1,50 NSTORE,1 NSOL,2,5548,U,X,rad_disp VARNAM,uradial,rad_disp PLTIME,1,50 XVAR,0 SPREAD,0 PLCPLX,0 PLVAR,rad_disp