【讨论】请大家看看这么一个“简单”的题目，我怎么算也不通过！

chenhu

这是以前luckier的贴子，可我不知怎么算也总是说在载荷点102，103过约束，其warning形式如下：
  
  ***WARNING: SOLVER PROBLEM.  ZERO PIVOT WHEN PROCESSING NODE 102 D.O.F. 2
  Typically a zero pivot is associated with an overconstraint in the model.  
  However, ABAQUS was not able to indentify any chains of constraints that might  
  lead to an overconstraint at this node. This suggests that the model might be  
  in fact insufficiently constrained in this particular degree of freedom.  
  Please check the constraints used in this model.  
请大家帮忙看看！
  
*heading
My first problem
*node
101,0,0,0
102,3,0,0
103,7,0,0
104,10,0,0
*element,type=t2d2,elset=eall
1,101,102
2,102,103
3,103,104
*solid section,elset=eall,material=steel
1,
*material,name=steel
*elastic
30e6,0.3
*step
*static
*boundary
101,encastre
104,encastre
*cload
102,2,-1000
103,2,-1000
*node print
u,rf,
*el print  
s,
*endstep

wjytj

Truss单元只能承担轴线力，可是你的荷载却是垂直于杆轴线的。
将你的单元类型换成梁单元B21吧，相应的定义梁单元的Section Property。

chenhu

谢谢版主！感觉看abaqus都木了，以前光看资料，没写过一个;inp，头一次就这样，真不爽！
改了一下，顺便还想问一下：
*element，elset=eall,type=b21
......
*beam section,elset=eall,material=steel，section=box
0.2,0.2,0.03,0.03,0.03,0.03
  
算出来了，那么我想看梁截面的应力分布，可不可以实现！？谢谢！

wjytj

如果你定义相应的Section Point可能可以,我也不会:I