我用ANSYS做了一个直径200米充气膜结构的找形分析，克可是我改了很多次就是不收敛，很苦恼！下面是命令流，希望大家知道一下！
FINISH
/CLEAR
/PREP7

A=100
ET,1,SHELL41
KEYOPT,1,1,2
MP,EX,1,9E5
MP,PRXY,1,0.3
MP,ALPX,1,10
R,1,0.001
TREF,0
CYL4,,,A,90

ASEL,ALL
AATT,1,1,1
LSEL,S,LENGTH,,A
LESIZE,ALL,,,200
LSEL,INVE
LESIZE,ALL,,,200
MSHAPE,1,2D
MSHKEY,1
ASEL,ALL
AMESH,ALL
ARSYM,X,ALL
ARSYM,Y,ALL
NUMMRG,ALL


/SOLU
ANTYPE,STATIC
NLGEOM,ON
NROPT,FULL
SSTIF,ON
AUTOTS,ON
NSUBST,20
LNSRCH,ON
PRED,ON
CNVTOL,F,,0.01
ALLSE

LSEL,S,RADIUS,,A
DL,ALL,,UX
DL,ALL,,UY
DL,ALL,,UZ


SFA,1,,PRES,500
SFA,2,,PRES,500
SFA,3,,PRES,500
SFA,4,,PRES,500


ASEL,ALL
BFA,ALL,TEMP,-1
SOLVE


我同学说是跨度太大，就不容易收敛了，不知道怎么回事？