Author Topic: soil column model  (Read 2631 times)

mv_cutti

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soil column model
« on: April 16, 2021, 07:46:05 PM »
Hi everybody,
I wanna ask you this question.
I tried to compare the two files that I had attached below.
These two files are the same model written in two different ways.
I don't understand why they give me different results in term of surface displacement.
Can someone help me???
  :-\

charles

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Re: soil column model
« Reply #1 on: April 17, 2021, 04:42:54 PM »
Hello, thanks for sharing this.
Could you provide more info: what are two different ways to write the models?

mv_cutti

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Re: soil column model
« Reply #2 on: April 18, 2021, 07:06:09 PM »
I attached two .tcl files for sharing my work. They are the same model, have the same geometry, the same material, the same elemente, the same boundary conditions but they are written with two different syntax (if you open the .tcl files you see what I'm saying) and so I expected the same results but aren't. I don't understand where I'm wrong  :-[

charles

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Re: soil column model
« Reply #3 on: April 18, 2021, 11:28:42 PM »
Those tcls files are not exactly the same.
Any small difference could cause discrepancies in the results.

But looking at the figure, they are very close.

mv_cutti

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Re: soil column model
« Reply #4 on: April 20, 2021, 11:34:39 PM »
Where they are different? I attached here the file testmodify.tcl in which I have changed the order of the comand but is the same as the test.tcl file that I have attached before

charles

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Re: soil column model
« Reply #5 on: April 20, 2021, 11:53:20 PM »
At least the "#switch material stage from elastic to plastic" is different.

mv_cutti

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Re: soil column model
« Reply #6 on: April 22, 2021, 12:47:34 PM »
Yes, is different the syntax but the command is the same.
In the first case I "set nonlinear 1" and then I write the command "updateMaterialStage -material materialtag -stage $nonlinear"
In the second case I directly used the comman "updateMaterialStage -material materialtag -stage 1"
Why did you say that they are different?


charles

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Re: soil column model
« Reply #7 on: April 24, 2021, 04:11:19 PM »
In one file you are updating mat 1-5, in another you are updating 1-5 and 100-500, tho you don't have 100-500 defined.
Not sure if this will cause differences in the results, but it is an example of the differences in your input.
Why did you say they are the same?

Other differences that might also affect results including:
1. The precision format, for example, 2.8000000e+01 vs 28

2.The coordinate system.
In one file the second dof is the gravity direction.
In the other file the third dof is the gravity direction.
I know there is no difference for human understanding (if you've taken care of all the directions when you create the node, elements, loads),
but it might be different for the preprocessor or solver to understand.