我给一根梁的两端各施加了沿着Y轴负方向的相同位移，按道理来说整根梁应该沿着Y轴的负方向移动，但实际情况是产生了X正向的位移，变形图如图所示，蓝色的线条表示变形后的形状，白色的虚线是原始形状。请问是什么原因，我贴出了我的命令流，恳请高人指点，不胜感激！

!***********************

/PREP7

!***********************

!******Element Type******

ET,1,SOLID185

ET,2,BEAM188

!************Sections************

SECTYPE,   1, BEAM, CSOLID, , 0

SECOFFSET, CENT

SECDATA,0.0051,0,0,0,0,0,0,0,0,0,0,0

!************meshing************

MP,DENS,1,7800 

MP,EX,1,2.06e11

MP,NUXY,1,0.3

!************Modeling************

!*Creat a cable

r=0.0051

length=0.05

k,1,0,r,0

k,2,0,r,length

!***line***

lstr,1,2

!************meshing************

lATT,1,,2,,,

LESIZE,ALL,0.001, , , ,1, , ,1,

LMESH,All

!************Loads************

DK,1, ,r, ,     0,ALL,UY, , , , ,

DK,2, ,r, ,0,ALL,UY, , , , ,

!***********************

/SOLU

!***********************

solve

!***********************

/POST1

!***********************

SET,FIRST  

PLDISP,1

PLNSOL, U,SUM, 0,1.0

/ESHAPE,1.0