Ansys: ANSYS deflection is different from the actual deflection

[Gilesk]

I am trying to model a simply supported beam with a point load at the center to show that ANSYS will give the correct deflection. When I run the analysis the deflection that ANSYS gives is different then what the actual should be. The deflection Ansys gives is 0.020348 meters when the actual deflection should be 0.02604 meters according to beam theory. Below is my command file for the beam. I would be grateful if anyone could help me figure out why my deflection is different.

/BATCH
/input,menust,tmp,'',,,,,,,,,,,,,,,,1

WPSTYLE,,,,,,,,0
/NOPR
KEYW,PR_SET,1
KEYW,PR_STRUC,1
KEYW,PR_THERM,0
KEYW,PR_FLUID,0
KEYW,PR_ELMAG,0
KEYW,MAGNOD,0
KEYW,MAGEDG,0
KEYW,MAGHFE,0
KEYW,MAGELC,0
KEYW,PR_MULTI,0
KEYW,PR_CFD,0
/GO

/units,si
/PREP7
!*


N,1,0,0,0
N,2,5
N,3,10

MPTEMP
MPTEMP,1,0

ET,1,BEAM188
MPDATA,EX,1,,200e9
MPDATA,PRXY,1,,0
sectype,1,beam,asec
secdata,0.1,1e-4,0,1e-4,0,1e-7
TYPE,1
REAL,1
SECNUM,1
MAT,1
E,1,2
E,2,3

D, 1,UX , 0.00000000 , 0.00000000
D, 1,UY , 0.00000000 , 0.00000000
D, 1,UZ , 0.00000000 , 0.00000000
D, 1,ROTX , 0.00000000 , 0.00000000
D, 1,ROTY , 0.00000000 , 0.00000000
D, 3,UX , 0.00000000 , 0.00000000
D, 3,UY , 0.00000000 , 0.00000000
D, 3,UZ , 0.00000000 , 0.00000000
D, 3,ROTX , 0.00000000 , 0.00000000
D, 3,ROTY , 0.00000000 , 0.00000000
F,2,FY,-25000
/solu
solve

 

[flash3780]

Looks like you're over-constrained, no? A simply supported beam will need to be able to translate in the x-direction on one side.

Perhaps that last part should be:

D,      1,UX  ,  0.00000000    ,  0.00000000    
D,      1,UY  ,  0.00000000    ,  0.00000000    
D,      1,UZ  ,  0.00000000    ,  0.00000000     
D,      1,ROTX  ,  0.00000000    ,  0.00000000    
D,      1,ROTY  ,  0.00000000    ,  0.00000000      
D,      3,UX  ,  0.00000000    ,  0.00000000
D,      3,UY  ,  0.00000000    ,  0.00000000    
D,      3,ROTX  ,  0.00000000    ,  0.00000000    
D,      3,ROTY  ,  0.00000000    ,  0.00000000
F,2,FY,-25000

 

[flash3780]

Oops... deleted the wrong line. I meant to say, perhaps the last part should be:

D,      1,UX  ,  0.00000000    ,  0.00000000    
D,      1,UY  ,  0.00000000    ,  0.00000000    
D,      1,UZ  ,  0.00000000    ,  0.00000000     
D,      1,ROTX,  0.00000000    ,  0.00000000    
D,      1,ROTY,  0.00000000    ,  0.00000000      
D,      3,UY  ,  0.00000000    ,  0.00000000    
D,      3,UZ  ,  0.00000000    ,  0.00000000
D,      3,ROTX,  0.00000000    ,  0.00000000    
D,      3,ROTY,  0.00000000    ,  0.00000000
F,2,FY,-25000