请大家帮我看看这是什么问题

我做了一个模型试验，想实现梁弯曲时两端的平断面假设，采用了cerig命令，求解时出现这样的错误：Constraint equation 1 has unused node 120000.以下是我的原命令流，希望大家帮我看看：
finish
/clear
/prep7

et,1,shell63

mp,ex,1,2.06E5
mp,prxy,1,0.3
mp,dens,1,7850e-9

R,5,5

K,1,0,0,0,
K,2,0,0,40,
K,3,0,0,80,
K,4,0,50,80,
K,5,0,100,80,
K,6,0,100,40,
K,7,0,100,0,
K,8,0,50,0,
K,9,0,50,40,
K,10,1000,0,0,


LSTR, 1, 2
LSTR, 2, 3
LSTR, 3, 4
LSTR, 4, 5
LSTR, 5, 6
LSTR, 6, 7
LSTR, 7, 8
LSTR, 8, 1
LSTR, 8, 9
LSTR, 9, 4
LSTR, 2, 9
LSTR, 9, 6
LSTR, 1, 10
FLST,2,2,4,ORDE,2
FITEM,2,1
FITEM,2,8
LDELE,P51X, , ,1


LSEL,ALL
LPLOT

ADRAG,7,6,12,9,,,13
ADRAG,5,4,10,12,,,13
ADRAG,11,10,3,2,,,13

ALLS
APLOT
ARSYM,Y,ALL
ALLS
ARSYM,Z,ALL

NUMMRG,ALL

ALLS
APLOT
REAL,
ESIZE,10
AATT,1,5,1
AMESH,ALL
AREVERSE,ALL
ASEL,S,LOC,Y,-50,50
ASEL,R,LOC,Z,80
AREVERSE,ALL
ASEL,S,LOC,Y,-50,50
ASEL,R,LOC,Z,-80
AREVERSE,ALL
ASEL,S,LOC,Y,50
ASEL,A,LOC,Y,-50
AREVERSE,ALL

NSEL,S,LOC,X,0
CM,NFOR,NODE
NSEL,S,LOC,X,1000
CM,NAFT,NODE
ALLS
CM,A0,AREA

!定义前后独立点
N,120000,0,0,0,,,,
N,120001,1000,0,0,,,,

NPLOT
CMSEL,S,NFOR
NSEL,A,,,120000
CERIG,120000,ALL,ROTX,ROTY,ROTZ

CMSEL,S,NAFT
NSEL,A,,,120001
CERIG,120001,ALL,ROTX,ROTY,ROTZ
ALLS
EPLOT

/SOLU
D,120000,UY,0,,,UZ
D,120001,UX,0,,,UY,UZ,ROTX
ALLS
acel,,,9.8
solve