经常被问，现写上完整的地应力平衡方法（希望加精）

loveestboy1981

由于老板项目多，自己论文忙，好长一段时间都没来SIMWE了，一上来就收到不少朋友的消息，问我的地应力平衡方法，现在我把整个过程详细说明一下，希望对大家有所帮助。
地应力平衡方法：
第一步：建立模型，材料，分析步（GEOSTATIC）
第二步：施加荷载，LOAD，选择施加重力GRAVITY，在你想施加重力的方向输入数值9.8
第三步：在命令行中输入mdb.models['模型名字'].setValues(noPartsInputFile=ON)  (请严格按照
               这个格式，注意大小写的字母)
第四步：提交J0B，完成后
第五步：按以下步骤,Roport---Report Field Output---选中S11,S22,S33,S12,S13,S23---Name:XX.INP
               ---Write中选择Field Output-------------ok!!!
第六步：用软件(推荐使用UltraEdit很好编辑的)打开XX.INP，保存格式内容
              单元号     S11    S22   S33   S12   S13   S23 （请注意，在保存内容中没有这一行的）
                 1        ,     .    ,   .    ,   .   ,    .   ,   .    ,   .
                 2        ,     .    ,   .    ,   .   ,    .   ,   .    ,   .
                 .         ,     .    ,   .    ,   .   ,    .   ,   .    ,   .
                 .         ,     .    ,   .    ,   .   ,    .   ,   .    ,   .
               这个结果文件是最重要的，在所保存的文件中只有数值部分，没有英文字母，没有
              上面那个“单元号”这一行，而且单元号前面也没有什么PART名字什么的，就是1，2.
              .......这些数字。
第七步：在ABAQUS----Model---Edit keywords---Model-1(这就是你的Model名字)---在材料属性后面
            加上：*initial conditions,type=stress,input=xx.inp     完成
第八步：重新提交JOB，OK
第九步：如果你还没有成功的话，那我只能说----------------我无语了。：）
ABAQUS的这项功能确实很不错。：）这个功能让基坑开挖、隧道开挖等的初始应力，开挖后的残余应力很好的显示；也可以很好的模拟铁路设计中的工后沉降的概念，在地应力平衡后，加上荷载所得沉降即为工后沉降；也很好的模拟了桩土复合地基的问题，如果没有初始应力的模拟，使土对桩产生了挤压应力，从而通过设定摩擦系数就可以模拟了桩与土之间的摩擦力；除此之外，在进行挡土墙计算时也需要ABAQUS的这项功能，反正很多都用得着。
希望我的建议能帮助初学者（其实我也是初学者，呵呵）很快掌握这个技巧。

xiqinma

An initial condition has been specified on element 0 but this element has not been defined

An initial condition has been specified on element 0 but this element has not been defined

An initial condition has been specified on element 0 but this element has not been defined

An initial condition has been specified on element 0 but this element has not been defined

An initial condition has been specified on element 0 but this element has not been defined

An initial condition has been specified on element 0 but this element has not been defined

An initial condition has been specified on element 0 but this element has not been defined

An initial condition has been specified on element 0 but this element has not been defined

An initial condition has been specified on element 0 but this element has not been defined

An initial condition has been specified on element 0 but this element has not been defined

An initial condition has been specified on element 0 but this element has not been defined

An initial condition has been specified on element 0 but this element has not been defined

An initial condition has been specified on element 0 but this element has not been defined

An initial condition has been specified on element 0 but this element has not been defined

An initial condition has been specified on element 0 but this element has not been defined

An initial condition has been specified on element 0 but this element has not been defined

An initial condition has been specified on element 0 but this element has not been defined

An initial condition has been specified on element 0 but this element has not been defined

An initial condition has been specified on element 0 but this element has not been defined

An initial condition has been specified on element 0 but this element has not been defined

An initial condition has been specified on element 0 but this element has not been defined

An initial condition has been specified on element 0 but this element has not been defined

An initial condition has been specified on element 0 but this element has not been defined

An initial condition has been specified on element 0 but this element has not been defined

An initial condition has been specified on element 0 but this element has not been defined

An initial condition has been specified on element 0 but this element has not been defined

An initial condition has been specified on element 0 but this element has not been defined

An initial condition has been specified on element 0 but this element has not been defined

An initial condition has been specified on element 0 but this element has not been defined

An initial condition has been specified on element 0 but this element has not been defined

An initial condition has been specified on element 0 but this element has not been defined

An initial condition has been specified on element 0 but this element has not been defined

An initial condition has been specified on element 0 but this element has not been defined

An initial condition has been specified on element 0 but this element has not been defined

An initial condition has been specified on element 0 but this element has not been defined

An initial condition has been specified on element 0 but this element has not been defined

An initial condition has been specified on element 0 but this element has not been defined

An initial condition has been specified on element 0 but this element has not been defined

An initial condition has been specified on element 0 but this element has not been defined

An initial condition has been specified on element 0 but this element has not been defined

An initial condition has been specified on element 0 but this element has not been defined

An initial condition has been specified on element 0 but this element has not been defined

An initial condition has been specified on element 0 but this element has not been defined

An initial condition has been specified on element 0 but this element has not been defined

An initial condition has been specified on element 0 but this element has not been defined

An initial condition has been specified on element 0 but this element has not been defined

An initial condition has been specified on element 0 but this element has not been defined

An initial condition has been specified on element 0 but this element has not been defined

An initial condition has been specified on element 0 but this element has not been defined

An initial condition has been specified on element 0 but this element has not been defined

Error message limit reached. No further error messages will be reported.
Please see the dat file for more errors.

Analysis Input File Processor exited with an error.

这是什么原因啊？？跪求啊

hydyb

请问：桩土相互作用的怎么相互平衡啊？谢谢！

wyang0503

大侠们说的第三步在那里输入啊！

tzwjc

非常感谢loveestboy1981雪中送炭啊，太好了！
一、但是小弟还是没有做出来，图1是桩的应力，怎么是4个一组呢？见图1
二、我做的是个桩土共同作用，是两种重度不同的材料，所以出现这种现象，第二种材料又开始从1开始，见图2。
这怎么办啊？
对于成层土怎么考虑呢？桩土共同作用呢？

[ 本帖最后由 tzwjc 于 2007-1-26 00:54 编辑 ]

dava

加了，写得好，希望以后经常来讨论

tzwjc

原帖由 loveestboy1981 于 2007-1-25 21:10 发表
这个功能让基坑开挖、隧道开挖等的初始应力，开挖后的残余应力很好的显示；也可以很好的模拟铁路设计中的工后沉降的概念，在地应力平衡后，加上荷载所得沉降即为工后沉降；也很好的模拟了桩土复合地基的问题，如果没有初始应力的模拟，使土对桩产生了挤压应力，从而通过设定摩擦系数就可以模拟了桩与土之间的摩擦力 ...

是不是对于不同的材料不能用这种方法？

loveestboy1981

这种方法就是针对不同材料，形状不规则的模型的地应力平衡，我用这种方法对桩土复合地基，边坡，路基等都做过地应力平衡，效果都非常好，你所出现的这种情况是不是因为没有在提交JOB之前进行mdb.models['模型名字'].setValues(noPartsInputFile=ON) 这一步？如果做了的话就没有问题，看你的结果.INP文件，中间不应该有INT PT这一列。建议你先建立几个简单的模型先把这个方法掌握再进行更复杂的模型计算。

lzq6666oopp

兄弟，弹塑性算的效果怎么样阿？有时候弹塑性的不收敛呀

tzwjc

loveestboy1981 是个好人啊，等你的能力达到版主的水平做版主绝对没问题，诲人不倦，无私奉献。
我知道我的为什么出现1、2、3、4周期出现的原因了，桩我采用的是CAX8R单元，采用CAX4R单元就不这样了，那个1、2、3、4我猜想可能是那个单元的4个什么应力，以后我就采用CAX4R单元好了。

tzwjc

原帖由 loveestboy1981 于 2007-1-25 21:10 发表
第三步：在命令行中输入mdb.models['模型名字'].setValues(noPartsInputFile=ON)  (请严格按照这个格式，注意大小写的字母)
第四步：提交J0B，完成后
第五步：按以下步骤,Roport---Report Field Output---选中S11,S22,S33,S12,S13,S23---Name:XX.INP...

我两种方法我都试了，我觉得还是下面的命令简单，当然每个人不一样，习惯了都行：
*el print
s,
这个命令加在以下位置，非常方便

loveestboy1981

tzwjc，你太客气了，互相交流，互相进步。
lzq6666oopp，你说的弹塑性，如果是地应力平衡，不存在问题啊，如果不收敛，是不是因为你的C值设定的太小了。

lzq6666oopp

哦，也就是和参数有关了。。。谢谢。顶你下。这个问题越讨论越深刻的。

sdsdsd

各位大侠，我按照上面一步一步的作
怎么出现这样的情况啊

in keyword *INITIALCONDITIONS, file "Job-20.inp", line 439: Unknown assembly id 12.

in keyword *INITIALCONDITIONS, file "Job-20.inp", line 439: Unknown assembly id 13.

in keyword *INITIALCONDITIONS, file "Job-20.inp", line 439: Unknown assembly id 14.

in keyword *INITIALCONDITIONS, file "Job-20.inp", line 439: Unknown assembly id 15.

in keyword *INITIALCONDITIONS, file "Job-20.inp", line 439: Unknown assembly id 16.

in keyword *INITIALCONDITIONS, file "Job-20.inp", line 439: Unknown assembly id 17.

in keyword *INITIALCONDITIONS, file "Job-20.inp", line 439: Unknown assembly id 18.

急啊
请各位帮帮忙
谢谢阿

iisltyf

in keyword *INITIALCONDITIONS, file "initial-stress.inp", line 6991: Unknown part instance name 54-758
请教各位高手这是怎么回事？

Allen-2000

原帖由 sdsdsd 于 2007-3-18 12:15 发表
各位大侠，我按照上面一步一步的作
怎么出现这样的情况啊

in keyword *INITIALCONDITIONS, file "Job-20.inp", line 439: Unknown assembly id 12.

in keyword *INITIALCONDITIONS, file "Job-20.inp",  ...

也遇见过这种问题，尚未解决！
等高手解答！

eeaatt

确实学到不少东西啊！！！！！！！！！！

rocksoul

采用*initial conditions， type＝stress， input＝xxx.inp 该如何定义模型的侧压系数呢？
我就知道
initial conditions， type＝stress，geostatic
elset－name，0，0，100，10，1.2，1.2
可以定义侧压系数。
岩土用好的多涉及地质构造应力，使得地应力不是静水压力，如果适用input方式来做地应力平衡，那么怎么施加侧压系数呢？

zoey

好方法啊，多谢楼主的指导。

aba_aba

出现错误信息 Unknown assembly id 12， Unknown part instance name 54-758，请看

http://www.simwe.com/forum/viewthread.php?tid=753043

rocksoul

多个part组成的model如何操作呢？ 单元号前面加instance的 我没有操作成功，有弄过的指点下哦。

iisltyf

谢谢aba版主的指导！不过用这种方法，我就以geostaitc来说，当你模拟的对象存在接触，或者其他不容易收敛的原因，是不是直接用geostatic步不太合适？
还有我在模拟基坑时采用邓肯张模型，大家知道这是非线性弹性，加载卸载变形不一样（与应力历史有关），我采用上述方法好像位移还是步太理想，是不是跟你所选的本构模型有关？
第三个问题就是回贴中提到的关于怎么加水平向应力的问题，这个用type＝stress，当然很好用，但是采用计算重力荷载回代的方法就步知道了
盼版主回答，谢谢！

Allen-2000

原帖由 aba_aba 于 2007-4-16 20:44 发表
出现错误信息 Unknown assembly id 12， Unknown part instance name 54-758，请看

http://www.simwe.com/forum/viewthread.php?tid=753043

原来如此。
谢谢！