请教：承载力的求解

ilbluest

下面是我学习时做的例题，想计算这样一个简支梁的承载力。想请教大家，模型是否正确，接下来该如何求解。请GGJJ们不吝赐教啊，最好能好命令流贴上来，学习一下。
/prep7
et,1,63
r,1,0.024
mp,ex,1,2.06e11
mp,prxy,1,0.2
tb,bkin,1,2
tbdata,1,225e6,0
k,1,,,
k,2,1.49
k,3,1.49,0.224
k,4,,0.224
a,1,2,3,4
k,,,0.224,-0.2
k,,,,-0.2
a,1,4,5,6
agen,2,2,,,1.49
agen,2,1,,,,,-0.2
nummrg,kp
a,3,4,5,9
a,2,1,6,10
wpstyl,,
wprota,,,90
wpoffs,,,0.298
asbw,all
wpoffs,,,0.298
asbw,all
wpoffs,,,0.298
asbw,all
wpoffs,,,0.298
asbw,all
a,7,8,11,12
a,13,14,15,16
a,17,18,19,20
a,21,22,23,24
esize,0.2
lsel,s,loc,z,-0.1,-0.19
lesize,all,,,2
allsel,all
amesh,all
save
finish
/solu
dl,7,11,all
dl,11,6,uy
dl,11,6,uz

ljk0002

Finish
/clear
/prep7
et,1,63
r,1,24
mp,ex,1,2.06e5
mp,prxy,1,0.2
tb,bkin,1,2
tbdata,1,225,0
k,1,,,
k,2,1490
k,3,1490,224
k,4,,224
a,1,2,3,4
k,,,224,-200
k,,,,-200
a,1,4,5,6
agen,2,2,,,1490
agen,2,1,,,,,-200
nummrg,kp
a,3,4,5,9
a,2,1,6,10
wpstyl,,
wprota,,,90
wpoffs,,,298
asbw,all
wpoffs,,,298
asbw,all
wpoffs,,,298
asbw,all
wpoffs,,,298
asbw,all
a,7,8,11,12
a,13,14,15,16
a,17,18,19,20
a,21,22,23,24
esize,200
lsel,s,loc,z,-100,-190

lesize,all,,,2
allsel,all
amesh,all
WPCSYS,-1,0
finish
/solu
dl,7,11,all
dl,11,6,uy
dl,11,6,uz
asel,all
fyy=-100E6*0.75
F,83,FY,fyy
nlgeom,on
solc,on
pred,on
time,fyy
autots,on
nsubt,1000,
outres,all,all
solve
finish
/post26
nsol,2,83,u,y,uy
ESOL,3,78,83,S,EQV,
PROD,4,2, , , , , ,-1,-1,-1,
PROD,5,3,,,,,,,1E-3,1,1
/axlab,x,y_disp
/axlab,y,stresss_node_83_eqv
xvar,4
plvar,5
finish
save

[ 本帖最后由 ljk0002 于 2006-11-27 12:47 编辑 ]

ljk0002

极限载荷＝FY=-100E6*0.75*0.991781N

ilbluest

谢谢ljk0002的解答，另外我还想知道 极限载荷＝FY=-100E6*0.75*0.991781N 是怎么得出的，能否示下...

ljk0002

所加载为-100e6*0.75,收敛于time=0.991781
这只是个思路,要求真实的极限载和,网格要划的足够密.

[ 本帖最后由 ljk0002 于 2006-11-26 18:08 编辑 ]

ilbluest

怎样判定你所求的就是极限荷载或屈服荷载？

ilbluest

nsol,2,83,u,y,uy
/axlab,x,y_strain
一个是位移，一个是应变，取值不对...

ilbluest

算了下，命令流为：
/prep7
et,1,63
r,1,0.024
mp,ex,1,2.06e11
mp,prxy,1,0.2
!tb,kinh,1,1,2
!tbpt,,225e6/2.06e11,225e6
!tbpt,,280e6/1.1e11,260e6
tb,bkin,1
tbtemp,0
tbdata,,225e6,0
k,1,,,
k,2,1.49
k,3,1.49,0.224
k,4,,0.224
a,1,2,3,4
k,,,0.224,-0.2
k,,,,-0.2
a,1,4,5,6
agen,2,2,,,1.49
agen,2,1,,,,,-0.2
nummrg,kp
a,3,4,5,9
a,2,1,6,10
wpstyl,,
wprota,,,90
wpoffs,,,0.298
asbw,all
wpoffs,,,0.298
asbw,all
wpoffs,,,0.298
asbw,all
wpoffs,,,0.298
asbw,all
a,7,8,11,12
a,13,14,15,16
a,17,18,19,20
a,21,22,23,24
esize,,20
lsel,s,loc,z,-0.1,-0.19
lesize,all,,,10
allsel,all
amesh,all
save,modle,db
finish
/solu
dl,7,11,all
dl,11,6,uy
dl,11,6,uz
node_force=node(1.49/2,0.224,-0.2/2)
node_stress=node(1.49/2,0,-0.2/2)
antype,0
nlgeom,on
solc,on
autots,on
outres,all,all
lnsrch,on
nsubst,100,1000,1
neqit,500
fy=-100e6
f,node_force,fy,fy
solve
finish

ilbluest

后处理，查看REACTION-DISPLACEMENT曲线，突变点对应set=18 ,time=0.54675,于是极限荷载为F=100e6*0.54675N=54675KN。
请问大家这是否是合理的？

ilbluest

最后一步的变形图............................

zhangyp

可在后处理中list节点力或节点反力。。。