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girder modelled by shells again

girder modelled by shells again

girder modelled by shells again

(OP)
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


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