girder modelled by shells again

[SKJoe]

Hi,

below is an input file made in ansys10.0. Is a simly supported girder modelled by shell elemensts shell 181
subjected to uniform pressure on a top flange (-5N/mm2).
It has been made in order to verify use of shell 181 for
another bending dominated problem.

I want to know max normal stress : analytical solution is 792.53N/mm2, numerical is 795.8N/mm2 (???). But there is a discontinuity in stresses which will appear on the graf after the input file is input

1) could someone explain me the reason ? - is it a result of shear locking or is it something different ?

2) may i simly "kick out" this peak value from averaging ?

(path is set up to display Sx of bottom layer of bottom flange, but stresses in the top layer of bottom flange are strange too...)

/BATCH
/COM,ANSYS RELEASE 10.0 UP20050718 11:26:55 10/31/2005
!*
/NOPR
/PMETH,OFF,0
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
!*
/COM,
/COM,Preferences for GUI filtering have been set to display:
/COM, Structural
!*
/PREP7
!*
ET,1,SHELL181
!*
KEYOPT,1,1,0
KEYOPT,1,3,2
KEYOPT,1,8,2
KEYOPT,1,9,0
KEYOPT,1,10,0
!*
ET,2,SHELL181
!*
KEYOPT,2,1,0
KEYOPT,2,3,2
KEYOPT,2,8,2
KEYOPT,2,9,0
KEYOPT,2,10,0
!*
ET,3,SHELL181
!*
KEYOPT,3,1,0
KEYOPT,3,3,2
KEYOPT,3,8,2
KEYOPT,3,9,0
KEYOPT,3,10,0
!*
!*
MPTEMP,,,,,,,,
MPTEMP,1,0
MPDATA,EX,1,,210000
MPDATA,PRXY,1,,.3
sect,1,shell,,top-flange
secdata, 50,1,0,3
secoffset,BOT
seccontrol,0,0,0, 0, 1, 1, 1
sect,2,shell,,web
secdata, 50,1,0.0,3
secoffset,MID
seccontrol,,,, , , ,
sect,3,shell,,bottom-f
secdata, 50,1,0,3
secoffset,TOP
seccontrol,0,0,0, 0, 1, 1, 1
RECTNG,,8000,-100,,
RECTNG,,8000,,100,
NUMMRG,KP, , , ,LOW
FLST,3,2,5,ORDE,2
FITEM,3,1
FITEM,3,-2
AGEN,2,P51X, , , , ,650, ,0
WPSTYLE,,,,,,,,1
wpstyle,50,100,-1000,1000,20,0,0,,5
wpro,,-90.000000,
RECTNG,,8000,,-650,
wpro,,,90.000000
wpoff,0,0,100
FLST,2,5,5,ORDE,2
FITEM,2,1
FITEM,2,-5
ASBW,P51X
wpoff,0,0,100
FLST,2,10,5,ORDE,2
FITEM,2,6
FITEM,2,-15
ASBW,P51X
wpoff,0,0,3800
FLST,2,15,5,ORDE,8
FITEM,2,1
FITEM,2,-5
FITEM,2,7
FITEM,2,9
FITEM,2,11
FITEM,2,13
FITEM,2,15
FITEM,2,-20
ASBW,P51X
wpoff,0,0,3800
FLST,2,20,5,ORDE,2
FITEM,2,6
FITEM,2,-25
ASBW,P51X
wpoff,0,0,100
FLST,2,25,5,ORDE,9
FITEM,2,1
FITEM,2,-5
FITEM,2,7
FITEM,2,-9
FITEM,2,11
FITEM,2,13
FITEM,2,-20
FITEM,2,23
FITEM,2,-30
ASBW,P51X
NUMMRG,KP, , , ,LOW
!*
LOCAL,11,0,0,0,0, , , ,1,1,
FLST,5,12,5,ORDE,10
FITEM,5,11
FITEM,5,13
FITEM,5,18
FITEM,5,-19
FITEM,5,21
FITEM,5,-24
FITEM,5,28
FITEM,5,-29
FITEM,5,33
FITEM,5,-34
CM,_Y,AREA
ASEL, , , ,P51X
CM,_Y1,AREA
CMSEL,S,_Y
!*
CMSEL,S,_Y1
AATT, 1, , 1, 11, 1
CMSEL,S,_Y
CMDELE,_Y
CMDELE,_Y1
!*
FLST,5,6,5,ORDE,6
FITEM,5,15
FITEM,5,20
FITEM,5,25
FITEM,5,30
FITEM,5,32
FITEM,5,35
CM,_Y,AREA
ASEL, , , ,P51X
CM,_Y1,AREA
CMSEL,S,_Y
!*
CMSEL,S,_Y1
AATT, 1, , 2, 11, 2
CMSEL,S,_Y
CMDELE,_Y
CMDELE,_Y1
!*
FLST,5,12,5,ORDE,9
FITEM,5,6
FITEM,5,-10
FITEM,5,12
FITEM,5,14
FITEM,5,16
FITEM,5,-17
FITEM,5,26
FITEM,5,-27
FITEM,5,31
CM,_Y,AREA
ASEL, , , ,P51X
CM,_Y1,AREA
CMSEL,S,_Y
!*
CMSEL,S,_Y1
AATT, 1, , 3, 11, 3
CMSEL,S,_Y
CMDELE,_Y
CMDELE,_Y1
!*
FLST,5,71,4,ORDE,17
FITEM,5,2
FITEM,5,4
FITEM,5,-12
FITEM,5,14
FITEM,5,-37
FITEM,5,41
FITEM,5,43
FITEM,5,-50
FITEM,5,53
FITEM,5,-63
FITEM,5,67
FITEM,5,70
FITEM,5,-76
FITEM,5,79
FITEM,5,-83
FITEM,5,86
FITEM,5,-89
CM,_Y,LINE
LSEL, , , ,P51X
CM,_Y1,LINE
CMSEL,,_Y
!*
LESIZE,_Y1,25, , , , , , ,1
!*
FLST,5,30,5,ORDE,2
FITEM,5,6
FITEM,5,-35
CM,_Y,AREA
ASEL, , , ,P51X
CM,_Y1,AREA
CHKMSH,'AREA'
CMSEL,S,_Y
!*
MSHKEY,1
AMESH,_Y1
MSHKEY,0
!*
CMDELE,_Y
CMDELE,_Y1
CMDELE,_Y2
!*
!*
/COM, CONTACT PAIR CREATION - START
CM,_NODECM,NODE
CM,_ELEMCM,ELEM
CM,_KPCM,KP
CM,_LINECM,LINE
CM,_AREACM,AREA
CM,_VOLUCM,VOLU
/GSAV,cwz,gsav,,temp
! Define surface-based constraint type of pair
MAT,1
R,3
REAL,3
ET,4,170
ET,5,175
KEYOPT,5,12,5
KEYOPT,5,4,0
KEYOPT,5,2,2
KEYOPT,4,2,1
KEYOPT,4,4,111111
TYPE,4
! Create a pilot node
! At center of mass of contact geometric entities
CSYS,0
N,13804, 100.0,-8.10686628938e-014,0
CSYS,11
TSHAP,PILO
E,13804
! Generate the contact surface
ASEL,S,,,7
ASEL,A,,,9
ASEL,A,,,16
ASEL,A,,,17
CM,_CONTACT,AREA
TYPE,5
NSLA,S,1
ESLN,S,0
ESURF
*SET,_REALID,3
ALLSEL
ESEL,ALL
ESEL,S,TYPE,,4
ESEL,A,TYPE,,5
ESEL,R,REAL,,3
/PSYMB,ESYS,1
/PNUM,TYPE,1
/NUM,1
EPLOT
ESEL,ALL
ESEL,S,TYPE,,4
ESEL,A,TYPE,,5
ESEL,R,REAL,,3
CMSEL,A,_NODECM
CMDEL,_NODECM
CMSEL,A,_ELEMCM
CMDEL,_ELEMCM
CMSEL,S,_KPCM
CMDEL,_KPCM
CMSEL,S,_LINECM
CMDEL,_LINECM
CMSEL,S,_AREACM
CMDEL,_AREACM
CMSEL,S,_VOLUCM
CMDEL,_VOLUCM
/GRES,cwz,gsav
CMDEL,_TARGET
CMDEL,_CONTACT
/COM, CONTACT PAIR CREATION - END
ALLSEL,ALL
!*
/COM, CONTACT PAIR CREATION - START
CM,_NODECM,NODE
CM,_ELEMCM,ELEM
CM,_KPCM,KP
CM,_LINECM,LINE
CM,_AREACM,AREA
CM,_VOLUCM,VOLU
/GSAV,cwz,gsav,,temp
! Define surface-based constraint type of pair
MAT,1
R,4
REAL,4
ET,6,170
ET,7,175
KEYOPT,7,12,5
KEYOPT,7,4,0
KEYOPT,7,2,2
KEYOPT,6,2,1
KEYOPT,6,4,111111
TYPE,6
! Create a pilot node
! At center of mass of contact geometric entities
CSYS,0
N,13805, 7900.0,1.89626803149e-013,0
CSYS,11
TSHAP,PILO
E,13805
! Generate the contact surface
ASEL,S,,,6
ASEL,A,,,10
ASEL,A,,,12
ASEL,A,,,31
CM,_CONTACT,AREA
TYPE,7
NSLA,S,1
ESLN,S,0
ESURF
*SET,_REALID,4
ALLSEL
ESEL,ALL
ESEL,S,TYPE,,6
ESEL,A,TYPE,,7
ESEL,R,REAL,,4
/PSYMB,ESYS,1
/PNUM,TYPE,1
/NUM,1
EPLOT
ESEL,ALL
ESEL,S,TYPE,,6
ESEL,A,TYPE,,7
ESEL,R,REAL,,4
CMSEL,A,_NODECM
CMDEL,_NODECM
CMSEL,A,_ELEMCM
CMDEL,_ELEMCM
CMSEL,S,_KPCM
CMDEL,_KPCM
CMSEL,S,_LINECM
CMDEL,_LINECM
CMSEL,S,_AREACM
CMDEL,_AREACM
CMSEL,S,_VOLUCM
CMDEL,_VOLUCM
/GRES,cwz,gsav
CMDEL,_TARGET
CMDEL,_CONTACT
/COM, CONTACT PAIR CREATION - END
ALLSEL,ALL
FINISH
/SOL
FLST,2,1,1,ORDE,1
FITEM,2,13804
!*
/GO
D,P51X, , , , , ,UX,UY,UZ,ROTX,ROTZ,
FLST,2,1,1,ORDE,1
FITEM,2,13805
!*
/GO
D,P51X, , , , , ,UY,UZ,ROTX,ROTZ, ,
FLST,2,8,5,ORDE,8
FITEM,2,18
FITEM,2,-19
FITEM,2,23
FITEM,2,-24
FITEM,2,28
FITEM,2,-29
FITEM,2,33
FITEM,2,-34
/GO
!*
SFA,P51X,1,PRES,-5
/STATUS,SOLU
SOLVE
FINISH
/POST1
FLST,2,9,1
FITEM,2,52
FITEM,2,205
FITEM,2,206
FITEM,2,207
FITEM,2,204
FITEM,2,1077
FITEM,2,1078
FITEM,2,1079
FITEM,2,922
!*
PATH,bottom,9,30,20,
PPATH,P51X,1
PATH,STAT
!*
!*
RSYS,0
AVPRIN,0,0
SHELL,BOT
AVRES,2,
/EFACET,1
LAYER,0
FORCE,TOTAL
!*
AVPRIN,0,0,
!*
PDEF, ,S,X,AVG
/PBC,PATH, ,0
!*
PLPATH,SX