新手建模，寻求大神指导。

本人用link10单元模拟一根拉索，用beam188单元模拟索两端的锚具，但是在计算时会弹出如下的error

我在网上查找了一些说法，说是因为不收敛造成的。求各位大神和前辈指导一下，非常感谢！

这是我的命令流

Finish

/Clear,start

/UNITS,SI$/Com,structural$/Filename,cable tension$/TITLE,vibration model

/PREP7

EM=1.1e11

AREA1=0.005281$AREA2=0.008332$AREA3=0.001196$AREA4=0.007854

ET,1,LINK10

ET,2,188

MP,EX,1,EM

MP,PRXY,1,0.3

MP,DENS,1,8343.7

MP,REFT,1,0

MP,ALPX,1,1.6e-5  

R,3,AREA3

SECTYPE,1,BEAM,CSOLID

SECDATA,SQRT(AREA1/3.14)

SECTYPE,2,BEAM,CSOLID  

SECDATA,SQRT(AREA2/3.14)

SECTYPE,4,BEAM,CSOLID  

SECDATA,SQRT(AREA4/3.14)

LSEL,NONE

K,1,0,15.064,0

K,2,0,14.706,0

K,3,0,13.803,0

K,31,0,13.803,0

K,4,0,0.260,0

K,41,0,0.260,0

K,5,0,0,0    

L,1,2

LSEL,S,,,1

LATT,1,,2,,,,1

L,2,3

LSEL,S,,,2

LATT,1,,2,,,,2

L,31,41

LSEL,S,,,3

LATT,1,3,1

L,4,5

LSEL,S,,,4

LATT,1,,2,,,,4

LSEL,S,,,ALL

LESIZE,ALL,0.02$LMESH,ALL

CP,1,UX,20,65

CP,NEXT,UY,20,65

CP,NEXT,UZ,20,65

CP,NEXT,UX,67,745

CP,NEXT,UY,67,745

CP,NEXT,UZ,67,745

D,1,UX,,,,,UY,UZ,ROTX,ROTY

D,746,UX,,,,,UY,UZ,ROTX,ROTY

FINISH

/SOLU

ANTYPE,STATIC

OUTRES,ALL,ALL

$NLGEOM,ON$LNSRCH,ON$AUTOTS,ON$EMATWRITE,YES$ALLSEL

BFE,ALL,TEMP,1,-170.5                                                  

ALLSEL$ACEL,,9.8

SOLVE

!!模态分析（打开预应力开关）

FINISH

/SOLU

ANTYPE,MODAL$UPCOORD,1.0,ON$PSTRES,ON

MODOPT,LANB,50$MXPAND,50$ALLSEL$PSOLVE,EIGLANB

FINISH

/SOLU  

EXPASS,ON$PSOLVE,EIGEXP$ALLSEL$EPLOT