非线性分析
请高人指点一下 钢筋混凝土梁的非线性问题（算了几步就进行不下去了:@( ）/COM,
/COM,Preferences for GUI filtering have been set to display:
/COM,Structural
!*
/PREP7
!*
ET,1,SOLID65
!*
ET,2,LINK8
!*
ET,3,SOLID45
R,1, , , , , , ,
RMORE, , , , , , ,
RMORE, ,
!*
R,2,201.1,0,
!*
R,3,78.5,0,
!*
MPTEMP,,,,,,,,
MPTEMP,1,0
MPDATA,EX,1,,3.105e4
MPDATA,PRXY,1,,0.3
TB,MISO,1,1,18,0
TBTEMP,0
TBPT,,0.0002,6.21
TBPT,,0.0004,8.693
TBPT,,0.0006,12.106
TBPT,,0.0008,14.904
TBPT,,0.0010,17.095
TBPT,,0.0012,18.685
TBPT,,0.0014,19.681
TBPT,,0.00164,20.1
TBPT,,0.0018,19.866
TBPT,,0.002,19.075
TBPT,,0.0022,17.975
TBPT,,0.0024,16.760
TBPT,,0.0026,15.534
TBPT,,0.0028,14.372
TBPT,,0.0030,13.300
TBPT,,0.0032,12.326
TBPT,,0.0034,11.450
TBPT,,0.0036,10.664
TB,CONC,1,1,9,
TBTEMP,0
TBDATA,,0.5,0.9,2.01,-1,,
MPTEMP,,,,,,,,
MPTEMP,1,0
MPDATA,EX,2,,2.0e5
MPDATA,PRXY,2,,0.3
TB,BISO,2,1,2,
TBTEMP,0
TBDATA,,500,0,,,,
MPTEMP,,,,,,,,
MPTEMP,1,0
MPDATA,EX,3,,2.0e5
MPDATA,PRXY,3,,0.3
TB,BISO,3,1,2,
TBTEMP,0
TBDATA,,300,0,,,,
MPTEMP,,,,,,,,
MPTEMP,1,0
MPDATA,EX,4,,3.0e4
MPDATA,PRXY,4,,0.3
BLOCK,0,2000,0,400,0,-250,
/VIEW,1,1,1,1
/ANG,1
/REP,FAST
VATT, 1, 1, 1, 0
LSEL,S,LINE,,4,5,1
LSEL,A,LINE,,2,7,5
LESIZE,ALL,50
LSEL,INVE
LESIZE,ALL,25
LSEL,ALL
VMESH,ALL
!*************箍筋单元的建立************
NSEL,S,LOC,X,75,125
NPLOT
/VIEW,1,1
/REP,FAST
/PNUM,NODE,1
/REPLOT
TYPE,2
MAT,3
REAL,3
!通过循环建立第一圈箍筋
*DO,I,2664,2671,1
E,I,I+1
*ENDDO
*DO,I,2538,2545,1
E,I,I+1
*ENDDO
*DO,I,2546,2663,9
E,I,I+9
*ENDDO
*DO,I,2538,2655,9
E,I,I+9
*ENDDO
!复制第一圈箍筋，每隔100mm布置一圈箍筋
ESEL,S,TYPE,,2
EGEN,11,270,ALL,,,,,,,,100,0,0,
ALLSEL,ALL
!建立纵筋单元
TYPE,2
MAT,2
REAL,2
*DO,I,2529,7524,135
E,I,I+135
*ENDDO
ESEL,R,REAL,,2
EGEN,3,4,ALL,,,,,,,,0,0,100,
*DO,I,2403,7398,135
E,I,I+135
*ENDDO
*DO,I,2411,7406,135
E,I,I+135
*ENDDO
FLST,2,2,1
FITEM,2,7659
FITEM,2,2402
E,P51X
FLST,2,2,1
FITEM,2,7663
FITEM,2,2342
E,P51X
FLST,2,2,1
FITEM,2,7667
FITEM,2,2282
E,P51X
FLST,2,2,1
FITEM,2,7533
FITEM,2,2388
E,P51X
FLST,2,2,1
FITEM,2,7541
FITEM,2,2268
E,P51X
!*************垫块单元的建立************
BLOCK,50,350,400,425,0,-250,
BLOCK,950,1250,0,-25,0,-250,
VATT,4,,3
LSEL,S,LINE,,16,17,1
LSEL,A,LINE,,28,29,1
LSEL,A,LINE,,14,19,5
LSEL,A,LINE,,26,31,5
LESIZE,ALL,50
LSEL,INVE
LESIZE,ALL,25
LSEL,ALL
VMESH,ALL
ALLSEL,ALL
NUMMRG,NODE,0,,,LOW
NUMCMP,NODE
NUMMRG,KP,0,,,LOW
NUMCMP,KP
!*************施加位移约束************
NSEL,S,LOC,Y,-25,-25
NSEL,R,LOC,X,1100,1100
D,ALL,,,,,,,UY,UZ,,,
ALLSEL,ALL
ASEL,S,LOC,X,2000,2000
DA,6,SYMM
ALLSEL,ALL
NSEL,S,LOC,Y,425,425
NSEL,R,LOC,X,200,200
NSEL,R,LOC,z,-125,-125
F,ALL,FY,-100000
ALLSEL,ALL
!*************进入求解器************
/SOL
!*
CNVTOL,U, ,0.05,0, ,
!*
ANTYPE,0
NLGEOM,1 !打开大变形
NSUBST,50,, !子部
OUTRES,ERASE
OUTRES,ALL,1 !输出所有子部
AUTOTS,1 !打开自动时间步长
LNSRCH,1 !线性搜索
NEQIT,50 !迭代步数
PRED,ON,,ON !预测开关
TIME,1 !荷载步结束时间
SOLVE
出错信息：
One or more elements have become highly distorted.Excessive
distortion of elements is usually a symptom indicating the need for
corrective action elsewhere.Try incrementing the load more slowly
(increase the number of substeps or decrease the time step size).You
may need to improve your mesh to obtain elements with better aspect
ratios.Also consider the behavior of materials, contact pairs,
and/or constraint equations.If this message appears in the first
iteration of first substep, be sure to perform element shape checking. 初步分析，是你的网格划分不好，出现了畸形单元，建议检查网格划分。最好都划成六面体单元 我都是划分成的六面体单元啊，检查了几遍都没有查出问题，还请高人指点啊 荷载怎么就加到一个节点上？应该是加到那个钢板面上吧
同时约束也要整个钢板底面都约束吧，可能是你的局部反应太大造成的
要么就增大荷载子步，比如说nsubst，1000 原帖由 sysh320 于 2008-10-31 11:01 发表 http://www.chinavib.com/forum/images/common/back.gif
荷载怎么就加到一个节点上？应该是加到那个钢板面上吧
同时约束也要整个钢板底面都约束吧，可能是你的局部反应太大造成的
要么就增大荷载子步，比如说nsubst，1000
附图：应该是加载和约束设置错误吧 先谢啦哈:@) 。我是模拟实验的加载，实验加载是集中荷载啊；还有那个支座垫板，不知道要不要全部约束啊 约束不够吧，我全约束了下底面，计算看上去正常。约束不全会有刚体位移或旋转或单元扭曲的 谢谢各位啦，有问题再向各位请教哈:@D 刚试了下，还是算不下去啊，出错信息还是原来那样:'( 确定这个是几何非线性吗?
如果是的话,
就慢慢调试吧...
(1) 子步数和平衡迭代数可考虑加大,50有点小..
(2)可考虑修改默认收敛准则容差.把默认值适度加大. 只是材料非线性啊，我换了几种方式建模，每次都有一样的出错信息，还请高手指点啊 材料非线性的话,
打开大变形做什么?
大变形是解决几何非线性的..
页:
[1]