钢管节点非线性极限承载力的一些问题

elvin

近来用ansys算圆钢管K型节点的极限承载力，得到的结果始终不令人满意。下面列出我遇到的一些问题，请各位帮忙看一看。
1.在建模时，主管和支管我都是用的 线绕两个Key Point旋转360度来得到圆柱面。而由于网格划分的不同，我将主管分为了3部分，支管分为了两部分。这之后又用cpintf进行了耦合，这样做会不会对后面的结果产生影响，和不将其划分为几部分的做法相比，结果有多大的差别呢？
2.在非线性计算的时候，总是只算了十几个子步就solution is done了，而我发现和其他同学的对比结果，位移，特别是力的数值都很小，力只有1e-13KN左右，而我所加的荷载为400KN左右的拉力，如果是受压的方管，应该在支管产生的力已经很大了。这个的原因是什么呢？

我将命令流贴在下面了，请大家帮忙，我先谢谢各位了。
由于本人课题主要不是ansys分析，所以这方面比较外行，望大家说得明白一点，多谢了。

fini
/cle
/prep7  

et,1,shell43
mp,ex,1,2.06e5  !弦（压）、支  
mp,ex,2,2.06e10  !duan(gang)

mp,nuxy,1,0.28   
mp,nuxy,2,0.3
   
tb,biso,1   
tbdata,1,345,2060   !弦（压）、支

r,1,3  !弦   
r,2,2  !支  
r,4,25 !duan(gang)

*afun,deg
*SET,jiao1,45
*SET,s1,sin(jiao1)     
*SET,c1,cos(jiao1)   
*SET,r0,100
*SET,r1,60
*SET,r2,60
*SET,l0,20*r0
*SET,l1,10*r0
*SET,l2,10*r0
*SET,p,0
*SET,g,50

k,1,0,0,l0/2
k,2,0,0,-l0/2
k,3,r0,0,l0/2
k,4,r0,0,l0/6
k,5,r0,0,-l0/6
k,6,r0,0,-l0/2

k,11,0,0,0
k,12,s1*l1,0,c1*l1
k,13,s1*l1,0,-c1*l1
k,14,s1*l1/2,0,c1*l1/2
k,15,s1*l1/2,0,-c1*l1/2

k,16,0,0,r1/s1
k,17,0,0,-r1/s1
k,18,s1*l1,0,r1/s1+c1*l1
k,19,s1*l1,0,-r1/s1-c1*l1

l,3,4
l,4,5
l,5,6
l,11,14
l,14,12
l,11,15
l,15,13

arotat,1,,,,,,1,2,360
arotat,2,,,,,,1,2,360
arotat,3,,,,,,1,2,360
arotat,4,,,,,,16,18,360
arotat,5,,,,,,16,18,360
arotat,6,,,,,,17,19,360
arotat,7,,,,,,17,19,360

al,22,24,26,28
al,23,25,27,29

al,45,47,49,51
al,44,46,48,50

al,67,69,71,73
al,66,68,70,72

va,5,6,7,8,29,30
va,21,22,23,24,33,34
va,13,14,15,16,31,32

vptn,1,2,3
vdele,all

adele,29,36,1
adele,41,46,1
adele,51,56,1
adele,6
adele,7

arotat,20,,,,,,1,2,360
l,41,45
l,53,57
al,58,60,116
al,56,62,116
al,80,82,117
al,78,84,117
save

mshkey,0
aatt,1,1,1
esize,40
amesh,1,4,1
amesh,9,12,1
esize,20
amesh,5
amesh,8
esize,10
amesh,6
amesh,7

aatt,1,2,1
esize,10
amesh,37,40,1
amesh,47,50,1
esize,20
amesh,17,20,1
amesh,25,28,1

aatt,2,4,1
esize,20
amesh,13,16,1

!krefine,58,65,1,2,,smooth,on
nsel,all
cpintf,ux
cpintf,uy
cpintf,uz

/solu
d,node(0,-100,-1000),ux,0,,,,uy,uz !xian duan constrain
d,node(-92.388,-38.268,-1000),ux,0,,,,uy,uz
d,node(-70.711,-70.711,-1000),ux,0,,,,uy,uz
d,node(-38.268,-92.388,-1000),ux,0,,,,uy,uz
d,node(-100,0,-1000),ux,0,,,,uy,uz
d,node(-92.388,38.268,-1000),ux,0,,,,uy,uz
d,node(-70.711,70.711,-1000),ux,0,,,,uy,uz
d,node(-38.268,92.388,-1000),ux,0,,,,uy,uz
d,node(0,100,-1000),ux,0,,,,uy,uz
d,node(38.268,92.388,-1000),ux,0,,,,uy,uz
d,node(70.711,70.711,-1000),ux,0,,,,uy,uz
d,node(92.388,38.268,-1000),ux,0,,,,uy,uz
d,node(100,0,-1000),ux,0,,,,uy,uz
d,node(92.388,-38.268,-1000),ux,0,,,,uy,uz
d,node(38.268,-92.388,-1000),ux,0,,,,uy,uz
d,node(70.711,-70.711,-1000),ux,0,,,,uy,uz

f,node(0,-100,1000),fz,16666.7,,,            
f,node(-92.388,-38.268,1000),fz,16666.7,,,  
f,node(-70.711,-70.711,1000),fz,16666.7,,,
f,node(-38.268,-92.388,1000),fz,16666.7,,,
f,node(-100,0,1000),fz,16666.7,,,
f,node(-92.388,38.268,1000),fz,16666.7,,,
f,node(-70.711,70.711,1000),fz,16666.7,,,
f,node(-38.268,92.388,1000),fz,16666.7,,,
f,node(0,100,1000),fz,16666.7,,,
f,node(38.268,92.388,1000),fz,16666.7,,,
f,node(70.711,70.711,1000),fz,16666.7,,,
f,node(92.388,38.268,1000),fz,16666.7,,,
f,node(100,0,1000),fz,16666.7,,,
f,node(92.388,-38.268,1000),fz,16666.7,,,
f,node(38.268,-92.388,1000),fz,16666.7,,,
f,node(70.711,-70.711,1000),fz,16666.7,,,

d,node(664.68,40.000,749.53),ux,0,,,,uy,uz
d,node(664.68,20.000,749.53),ux,0,,,,uy,uz
d,node(664.68,0,749.53),ux,0,,,,uy,uz
d,node(664.68,-20.000,749.53),ux,0,,,,uy,uz
d,node(664.68,-40.000,749.53),ux,0,,,,uy,uz
d,node(664.68,60.000,749.53),ux,0,,,,uy,uz
d,node(664.68,-60.000,749.53),ux,0,,,,uy,uz

d,node(664.68,-40.000,-749.53),ux,0,,,,uy,uz
d,node(664.68,-20.000,-749.53),ux,0,,,,uy,uz
d,node(664.68,0,-749.53),ux,0,,,,uy,uz
d,node(664.68,20.000,-749.53),ux,0,,,,uy,uz
d,node(664.68,40.000,-749.53),ux,0,,,,uy,uz  
d,node(664.68,60.000,-749.53),ux,0,,,,uy,uz
d,node(664.68,-60.000,-749.53),ux,0,,,,uy,uz
   
save

ANTYPE,0
NLGEOM,on   
NSUBST,500,0,0  
ARCLEN,1,100,0.0000000001  
ARCTRM,U,10,node(-100,0,-1000),UY  
OUTRES,BASIC,all  
AUTOTS,OFF
LNSRCH,OFF
PRED,OFF,,OFF
EQSLV,SPARSE  
NROPT,FULL, ,OFF
PIVCHECK,ON  
SSTIF,On  
PSTRES,OFF  
NEQIT,15   
solve


/post26 !ya
numvar,30
nsol,2,node(100,0,100),u,y   
nsol,3,node(-100,0,0),u,y
rforce,6 ,node(100,0,100),f,y  
rforce,7 ,node(664.68,40.000,749.53),f,y
rforce,8 ,node(664.68,20.000,749.53),f,y  
rforce,9 ,node(664.68,0,749.53),f,y
rforce,10,node(664.68,-20.000,749.53),f,y
rforce,11,node(664.68,-40.000,749.53),f,y
rforce,12,node(664.68,-60.000,749.53),f,y
add,13,6 ,7 ,8 ,,,,1,1,1   
add,14,9 ,10,11,,,,1,1,1
add,15,13,14,12,,,,-1,-1,-1
add,16,15,,,F-force,,,1/1000
add,5,2,3,,displacement,,,-1,1  
prvar,5,16  
/axlab,x,Deflection(mm)
/axlab,y,Ya totle load(KN)  
/grid,1
/xrange,0,15
/yrange,0,100
xvar,5  
plvar,16

AaronSpark

solution is done表示计算收敛了,这个应该没什么问题

结果的差别可能是你单位没有统一,仔细检查一下你的单位