开孔补强圈建模

ffox

请教各位高人，我的补强圈面积理论上直径1600，故补强圈面积应该为2009600，而我的模型却有2011186，请赐教
finish
/clear
/title, external pressure cylinder with single nozzal
/COM,STRUCTURAL

/PREP7
ET,1,solid95
MPTEMP,1,20
mp,ex,1,2e5
mp,nuxy,1,0.3


cylind,510,500,0,2500,0,180
cylind,510,500,0,2500,180,360
cylind,510,500,2500,5000,0,180
cylind,510,500,2500,5000,180,360

cylind,515,510,0,5000,0,180
cylind,515,510,0,5000,180,360
vglue,all

wpoff,1500,,2500
wpro,,,90
CSWPLA,11,1,727/800,1,
K,100,-800,,,
K,101,800,,,
CSYS,4  
K,102,,727,,
csys,11
L, 101, 102
l,102,100
LSTR,       100,   101
LCOMB,13,14 ,0   
AL,13,15

VROTAT,7, , , , , ,100,101,360, ,
btol,1.81e-5
vadd,2,3,4,5
VGEN, ,6, , , , ,-1003, , ,1  
vovlap,all
btol,1e-5

VDELE,       2,19 ,17 ,1
VDELE,      20,21,1,1