请教：关于remove

tjuzlm

最近做基坑模型，开挖第一步时没问题，然后加板，再开挖

在加板的过程中被挖掉的土体产生了很大的位移，然后导致了数值奇异，这怎么办呢


我试过把挖掉的土体侧面顶面约束，但下面产生很大位移，如果整个土体都约束，下面的土体就没有位移了，这样都不行

abaqus好像是通过吧remove的单元刚度改为零实现开挖的吧

求助各位大侠，小弟感激不尽啊

vn501169

*model change，remove
数据行（单元号或单元集标签）
*model change，add
数据行（单元号或单元集标签）;
可以实现单元的生死问题。具体可以参考abaqus的online帮助文件。
如在一个分析步中：用下面的句子可描述杀死单元的情况：
*Step, name=Step-2
*Static
*model change,remove
PART-1-1.KAIWA
*Restart, write, frequency=0
*Output, field, variable=PRESELECT
*Output, history, variable=PRESELECT
*End Step

*Step, name=Step-1
eff
*Stati
0.0001, 1., 1e-05, 1
*model change,remove,
set name,
*other defination...

vn501169

这是帮助文档的内容

Removing elements

You can remove specified elements from the model in a general analysis step.
Just prior to the removal step, Abaqus/Standard stores the forces/fluxes that
the region to be removed is exerting on the remaining part of the model at
the nodes on the boundary between them. These forces are ramped down to zero
during the removal step; therefore, the effect of the removed region on the
rest of the model is completely absent only at the end of the removal step.
The forces are ramped down gradually to ensure that element removal has a
smooth effect on the model.

No further element calculations are performed for elements being removed,
starting from the beginning of the step in which they are removed. The
removed elements remain inactive in subsequent steps unless you reactivate
them as described below.
Input File Usage:               Use the following option to remove elements
from the model:


*MODEL CHANGE, TYPE=ELEMENT, REMOVE

tjuzlm

但是我作的模型在加板的那一步中挖掉的土体产生了很大的位移，到后面就数值奇异了，一点都算不过去
郁闷
搞了很久了  这个模型

vbgdvu

同问！
在进行瞬态分析时，通过remove挖掉的土体节点反而最终发生了数值奇异，难道remove没有使单元和节点失效吗？