请教一个ANSYS分析工字梁结构的问题

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请教一个ANSYS分析工字梁结构的问题

请大家帮忙解决个工字梁分析的问题，做出的弯矩图好像总不对，请大家赐教，小弟不胜感激
命令流如下
E=1.1e10
A=4.3
F=20000
p=800
W=1.86E-3
/prep7
/UNITS,SI
/PREP7
ET,1,BEAM188
MP,EX,1,E
MP,PRXY,1,0.3
SECTYPE,1, BEAM, I, , 0  
SECDATA,0.158,0.158,0.5,0.02,0.02,0.012,0,0,0,0!NO.50a  
K, ,,,,
K, ,A,,,
K, ,A,1,,
LSTR, 1, 2
LATT,1, ,1, , 3, ,1
LESIZE,1, , ,8, , , , ,1
LMESH, 1
FINISH
/SOL  
ANTYPE,0   
D,1, ,0, , , ,UX,UY, , , ,     
D,6, ,0, , , ,UY, , , , ,
D,2, ,0, , , ,UY, , , , ,  
F,4,FY,-F
SFBEAM,5,1,PRES,p,p, , , , ,
SFBEAM,6,1,PRES,p,p, , , , ,
SFBEAM,7,1,PRES,p,p, , , , ,
SFBEAM,8,1,PRES,p,p, , , , ,
/STATUS,SOLU
SOLVE   
FINISH  
/POST1  
SET,FIRST
ALLSEL
AVPRIN,0,0,
ETABLE,ISHEAR,SMISC, 5   
AVPRIN,0,0,
ETABLE,JSHEAR,SMISC, 18  
AVPRIN,0,0,
ETABLE,IMOMENT,SMISC, 3
AVPRIN,0,0,
ETABLE,JMOMENT,SMISC, 16
PLLS,ISHEAR,JSHEAR,1,0  
PLLS,IMOMENT,JMOMENT,1,0
PRETAB,ISHEAR,JSHEAR
PRETAB,IMOMENT,JMOMENT