• feng
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Topic: Tunnel excavation with "activityltf"?

Hello
I have some troubles in my structure.I want to make a simulation of roadway excavation.But I don't know how to remove the element.I think maybe I can use the "activityltf" to do that.But I don't know what is the main meaning of "activityltf".I need your help.
Thanks a lot.
Student Feng

2 Reply by bp

  • bp
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Re: Tunnel excavation with "activityltf"?

HI,
please refer to the examples deactivate_1.in and deactivate_2.in located in tests/sm directory. They illustrate activation/deactivation of elements.

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  • feng
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Re: Tunnel excavation with "activityltf"?

Thanks for your reply.I have checked the examples deactivate_1.in and deactivate_2.in.But I also have a question.I think after I use the 'activityltf' there will be some changes around the missing element (such as the displacement/strain/stress).I think there will be the stress concentration around the tunnel after excavation.But I didn't see any changes in paraview.
So could you please tell the real meaning of 'activityltf'?
Thanks a lot.

  • Registered: 25-06-2013
  • Posts: 241

Re: Tunnel excavation with "activityltf"?

Hi,

can you upload the input file?
Yhe activityltf refers to number of a time function which defines when the elements are switched on, or switched of.

5 Reply by feng (edited by feng 23-04-2018 10:41:31)

  • feng
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Re: Tunnel excavation with "activityltf"?

Hello,
The following file "a.in" is what I wrote.I use the "activityltf" in the line 237.So should I change the conditions or the load to get the displacement after the excavation?
Thanks a lot.

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  • Registered: 25-06-2013
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Re: Tunnel excavation with "activityltf"?

Hi, I can see some concentration after excavation in the paraview, see the attached file.
Which version of OOFEM are you using?

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  • feng
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Re: Tunnel excavation with "activityltf"?

Hello,
Thank you very much for your reply.I have seen your picture attached.Maybe I have some wrong understanding with the result of paraview.I just use the oofem-2.5.
And then,after the excavation,I just want to add the cable.But I can not set a new element in the rock(maybe a coordinate can only have a same dofs). So should I use the "activityltf" to drill a hole and then add a new element(with new material and dofs)? And also there will be a difficult to create the interface between the cable and the rock.
Could you give me some suggestions?
Thanks a lot.

  • Registered: 25-06-2013
  • Posts: 241

Re: Tunnel excavation with "activityltf"?

You can use activityltf for the cable and activate the cable after the hole is drilled, but I don't know what exactly you want to simulate so it is difficult to give some suggestions.

  • feng
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Re: Tunnel excavation with "activityltf"?

Hello
Thanks for you reply.For my project,I just want to simulate a complete process of tunnel excavation( including setting up the model,excavation,add cables).But my question is that how to add the cables after the excavation.Can I just add the cable in the rock(Because there will be a large number of elements if I drill the hole).And also how to modify the interface between the rock and cables(I think that the interface simulation is the most difficute part).
Thanks a lot.