Yade

JCFmat model parameters issue

Asked by Mahdi on 2023-08-28

I am using JCFmat for simulating the UCS of rock specimens.
When I assign the tensileStrength = 0.0, the UCS curve is controlled by the cohesion (70 MPa).
However, when I assign a value to the tensileStrength, the UCS response is controlled by tensileStrength.

What is the issue?

rockId = O.materials.append(
        JCFpmMat(young=10e9,
                 cohesion=70e6,
                 density=2500,
                 frictionAngle= 0.8,#radians(30),
                 tensileStrength=0.0e6,
                 poisson=0.2,
                 label='JCFmat')

Question information

Language:: English Edit question

Status:: Solved

For:: Yade Edit question

Assignee:: No assignee Edit question

Solved by:: Luc Scholtès

Solved:: 2023-08-30

Last query:: 2023-08-30

Last reply:: 2023-08-29

Link existing bug

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Yade Guide (yade-guide) said on 2023-08-28 (last edit on 2023-08-28):

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Robert Caulk (rcaulk) said on 2023-08-28:

Hey,

It is not immediately clear what the question is. When you assign tensile strength, the tensile strength plays a role. When you set the tensile strength to 0, it does not play a role.

So far everything makes sense. Can you elaborate?

Cheers,

Robert

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Yade Guide (yade-guide) said on 2023-08-28:

Hey mahdi2023, check out some related threads. This is an automated reply.

Title: "A problem with 'JCFmpMat'"
Question by qfxx-123 on 19 Jun 2023:
The user is seeking clarification on the differences between 'JCFpmMat' and 'FrictMat' when their tensile strength and cohesion are set to zero. Despite having similar structures, the results of the two triaxial tests were significantly different. The user wants to know why the sample is stress-free at the first iteration of a JCFPM simulation, the use of 'intR>1' in the engine when particles are touching each other, and how to edit the code if they want the results of 'JCFpmMat' to be same with 'FrictMat'. The user has set 'intR' to 0 and tried again, finding that the strength of the two methods is identical. They thanked the person for their guidance.
https://answers.launchpad.net/yade/+question/707022

Title: "JCFpmMat parameters define"
Question by voyagening on 29 Nov 2020:
The JCFpm parameters in YADE are used for simulating jointed materials like fractured rocks. These include 'cohesion' and 'jointCohesion', which account for different mechanical properties of the matrix and fractures, respectively. Additional parameters such as 'jointDilation' and 'jointSurface' allow for defining the dilation of jointed contacts following the physics of rock joints. Aaron expressed gratitude for a helpful explanation and plans to further research these concepts.
https://answers.launchpad.net/yade/+question/694253

Title: "How to set the parameters of JCFpmMat?"
Question by qfxx-123 on 11 Jul 2023:
The user is seeking clarification on how to set parameters in JCFpmMat, specifically tensileStrength and cohesion in relation to degree of interlocking. Luc provides guidance by suggesting defining the C/T ratio of BPM equal to compressive strength / tensile strength of the rock being modeled.
https://answers.launchpad.net/yade/+question/707257

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Mahdi (mahdi2023) said on 2023-08-28:

Hi Robert,

Many thanks for your reply!
I believe I've resolved the issue. The problem was with the value of "intRadius." I'm not entirely sure what it represents, but I increased it to 1.5, and now the model is functioning correctly.

Previously, when it was set to 1.3, the model was only controlled by tensile strength. However, increasing the cohesion had no observable effect.
Do you know what is "intRadius"?

Thanks

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