/com  quartz tube external pressure buckling (from STAR/al_150_long.1.txt) 
/com	qt3= round tube, thick endcaps, axial force, ball ends, ev buckle
p=100000	!unit force 1 bar
t=.003	!tube thickness
r=.0195	!tube radius, nom
l=1.2		!tube length
ndiv_long=100	!number of longitudinal elements
ndiv_circ=16	!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 ext. press. e_v_buckle, uz=0 1 bar unit press.
/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,3,r,180
k,4,r,270
k,5,,,l
l,2,3,ndiv_circ
l,3,4,ndiv_circ/2
l,4,2,ndiv_circ/2
l,1,5,ndiv_long,-3
/com	ADRAG, NL1, NL2, NL3, NL4, NL5, NL6, NLP1, NLP2, NLP3, NLP4, NLP5, NLP6
adrag,1,2,3,,,,4
amesh,all
/com	LESIZE, NL1, SIZE, ANGSIZ, NDIV, SPACE, KFORC, LAYER1, LAYER2, KYNDIV
l,1,2	!l11
l,1,3	!l12
l,5,6	!l13
l,5,7	!114
LESIZE,all,,,0.5*ndiv_circ
al,12,1,11
al,11,3,2,12
al,13,5,14
al,14,8,10,13
sfa,all,2,pres,p	!unit pressure of 100 kPa
real,2
amesh,4,7
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
fk,5,fz,-f
save
/com	SFA, AREA, LKEY, Lab, VALUE, VALUE2
fini
/solu
anty,0
/com	eqslv,sparse
pstress,on
solve
save
fini
/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