CBR test of aggregates

PFC
1

Hi all,

I am working on simulating the California Bearing Ratio test of aggregates in PFC3D. I am currently working on the generating the .stl file for the specimen. I am not sure how do I assign the loading conditions to the plunger and the boundary conditions to the walls of specimen. If someone has a script to perform CBR test can they please share it with me or guide me on how to perform it.

Many Thanks.

2

Dear Kamrankhan, Thank you for your use of PFC3D. I have created a PFC3D package (otPkg9.3) that models an oedometer test. The package can be downloaded from the link: {ShareFile}. You may find this to be of help.

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Thank you Dr. Potyondy for sharing the package. Your support is much appreciated.

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You are welcome. You may also find the material-modeling support package to be of use {Material-Modeling Support for PFC | US Minneapolis - Itasca Consulting Group, Inc.} — it supports triaxial compression tests.

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Thank you Dr. Potyondy for providing the links to the support packages. I’ve been exploring the material modelling support, and I understand that it currently supports testing and microstructural monitoring primarily for regular geometries such as cuboids.

However, I’m interested in extending its functionality to accommodate irregular shapes—for example, modeling aggregate particles—or to simulate CBR-type tests by importing .stl files representing a cylindrical mold and a penetration rod. Ideally, I’d like to apply a load to the penetration rod using a servo mechanism and monitor the resulting material response using the package.

Could you kindly advise whether there are any existing tutorials or documentation that could help guide such modifications?

Thank you once again for your continued support.

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Dear Kamrankhan, The material modeling support package provides standard rock-mechanics tests (direct tension and triaxial) on cylinders or rectangular cubes. It also creates spherical assemblies. The particles can be spheres or clumps. And there are some models that use polyhedra (rigid blocks). There has been much published work where people have used PFC to model realistic grains shapes (often as rigid blocks with geometries imported from STL files). This has been done by Ayat Alasadi, the student for whom I created the otPkg. I am sure that she would be happy to discuss this with you further, and perhaps, even share the extensions that she made to the otPkg to do this. I have done work related to modeling CBR, and it is available in the pavement design package (see Pavement-Design Package in PFC | US Minneapolis - Itasca Consulting Group, Inc.)

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In particular, look at the report {
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} that is contained in the Documentation directory of the pdPkg.

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Thank you again, Dr. Potyondy, for sharing your insights and the links to the pavement package. I truly appreciate you taking the time to respond.

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You are welcome. [I cannot just say this, because the post must be at least 20 characters. Well now it is.]

1 Like