Material calibration for flat accumulation

Kiran Purushothama Keshavan

Hey,

I have data for a particulate material which does not show angle of repose, rather it just accumulates on a flat plate layer by layer. I went through the material calibration method by which angle of repose can be determined by changing parameters like work of adhesion, coefficient of restitution, etc., on EDEM. 

I used altair Hyperstudy to observe change in angle of repose.

What is your suggestion on how I can study the variation of flat plate accumulation as a result based on the input parameters.
My experimental data shows 6mm of accumulation (with no angle of repose as a record) on flat plate for a span of 405 seconds.

Regards,
Kiran

Renan

Hi Kiran,

As long as you can replicate your physical experiment in EDEM, then you can use the same methodology used in the angle of repose calibration to calibrate your flat plate accumulation.

You can use HyperStudy to create a DOE to find which variables have the most influence on the results, then you can run, within HyperStudy, an optimization process to find the calibrated values for your contact parameters.

Best regards,
Renan

Kiran Purushothama Keshavan

Hey Renan,

Thanks for your reply, I'm having trouble at step one of your suggestion which is to replicate the physical experiment in EDEM. I tried getting a simulation for flat plate accumulation but the simulation duration from the experiment is 408seconds with very low particle density. 
Please suggest what you think I can do.

Regards,
Kiran

jerrinjobs

Kiran Purushothama Keshavan said:

Hey Renan,

Thanks for your reply, I'm having trouble at step one of your suggestion which is to replicate the physical experiment in EDEM. I tried getting a simulation for flat plate accumulation but the simulation duration from the experiment is 408seconds with very low particle density. 
Please suggest what you think I can do.

Regards,
Kiran

Hi Kiran

If you are able to perform an angle of repose test for your physical particulate material, you can replicate the test within EDEM and calibrate the EDEM inputs.

If the flat plate accumulation is the physical test that you have the data for, you can replicate a similar test in EDEM, and match the macro parameters of the test, like layer spread distance, etc - That was just an example - you are better equipped to understand the result data of the test.

Hope this helps.

Thanks,
Jerrin Job

Kiran Purushothama Keshavan

Hey Jerrin,

Thanks for the reply, the experimental data does not give me an angle of repose, instead the material is such that the accumulation on a flat plate is just a layer by layer accumulation which follows the profile of the plate. I have attached an image for your reference. 

Your opinion on this would be of great help to me.

 

Regards,

Kiran

jerrinjobs

Kiran Purushothama Keshavan said:

Hey Jerrin,

Thanks for the reply, the experimental data does not give me an angle of repose, instead the material is such that the accumulation on a flat plate is just a layer by layer accumulation which follows the profile of the plate. I have attached an image for your reference. 

Your opinion on this would be of great help to me.

 

Regards,

Kiran

Hi Kiran

Is your physical system of interest dynamic in nature? You could also try performing the dynamic angle of repose test, as opposed to a static angle of repose test, to be able to replicate the test within EDEM, and calibrate the inputs required.

Hope this helps.

Thanks,
Jerrin Job

Kiran Purushothama Keshavan

Hey Jerrin,

That is a nice idea, I myself have never tried dynamic angle of repose test. 

My test for particle accumulation is an excel sheet obtained from a sensor, it has data of accumulation for a time period of 405 seconds of the test.  The angle of repose is almost 0 for the entire length of the simulation, the material build up is layer by layer with no value for angle of repose.

Please comment on my situation. I just need to understand how I could make this work on EDEM.

Regards,

Kiran

jerrinjobs

Kiran Purushothama Keshavan said:

Hey Jerrin,

That is a nice idea, I myself have never tried dynamic angle of repose test. 

My test for particle accumulation is an excel sheet obtained from a sensor, it has data of accumulation for a time period of 405 seconds of the test.  The angle of repose is almost 0 for the entire length of the simulation, the material build up is layer by layer with no value for angle of repose.

Please comment on my situation. I just need to understand how I could make this work on EDEM.

Regards,

Kiran

Hi Kiran

I am having difficulty in understanding what you are asking and probably that is why I my previous responses did not help you.

'How I could make this work' - what does 'this' refer to here?

Are you able to perform new tests on your material? If yes, then perform a static angle or dynamic angle of repose test to calibrate the inputs. If you are unable to perform new tests, then you need to figure out a way to do that. Without test cases, it is possible to calibrate the material with your physical system of interest (which I am assuming in this case is the accumulation), but it is considerably more time-consuming, especially in your case, where the physical time period is so high with a large number of particles.

I am assuming your excel sheet has time versus layer thickness, and in this case, you should be able to vary particle-particle friction coefficients to calibrate how fast or slow the particles move on another layer, so that your physical test can be replicated.

Hope this helps.

Thanks,
Jerrin Job

Kiran Purushothama Keshavan

Hey,

By 'How I could make this work' I mean to ask if there's a way I could calibrate my material (which does not show any angle of repose).

Even though I perform the same tests on the material the outcome is likely going to be the same. I have attached an image from the test which shows particle accumulation. If you observe carefully the white layer on the black platform is the accumulation.

For sake of simplicity I could reduce the duration of the test to 100seconds where I should be seeing a flat accumulation of 2mm.

For the last part where you suggest if I could vary the particles particle friction coefficients to calibrate how fast or slow the particles move, I'd like to know if I can parameterize this process instead of running individual simulations to replicate the results.

Regards,

Kiran 

jerrinjobs

Kiran Purushothama Keshavan said:

Hey,

By 'How I could make this work' I mean to ask if there's a way I could calibrate my material (which does not show any angle of repose).

Even though I perform the same tests on the material the outcome is likely going to be the same. I have attached an image from the test which shows particle accumulation. If you observe carefully the white layer on the black platform is the accumulation.

For sake of simplicity I could reduce the duration of the test to 100seconds where I should be seeing a flat accumulation of 2mm.

For the last part where you suggest if I could vary the particles particle friction coefficients to calibrate how fast or slow the particles move, I'd like to know if I can parameterize this process instead of running individual simulations to replicate the results.

Regards,

Kiran 

Hi Kiran

You can use EDEMCal/Altair HyperStudy to parametrize your calibration process, and both of them can run multiple simulations for you, eliminating the manual effort to set up each case.

You can find information on EDEMCal here: https://help.altair.com/edem/EDEM__Cal.htm

You can find information on HyperStudy here: https://community.altair.com/community/en?id=community_blog&sys_id=78fb1a68db970d90e8863978f4961905

If you are also trying to optimize within HyperStudy, you need to define an output response (from the Excel sheet you have) to calibrate against.

Since you are not able to get an angle for the static angle of repose tests (because of the nature of your material) is why I recommended you perform a dynamic angle of repose test. It is likely that you will get an angle in that case especially if your surface is rough and the rotational velocity is high.

Hope this helps.

Thanks,
Jerrin Job

Kiran Purushothama Keshavan

Hey Jerrin,

Thanks for pointig to EDEM cal I had no idea about this. I have used static angle of repose test but like you said maybe I'll have to look into dynamic angle of test (probably have to set up an experiment).

1. But do we have tutorials for 'EDEM cal'?

2. How do I access EDEM cal?

Regards,

Kiran

Renan

Kiran Purushothama Keshavan said:

Hey Jerrin,

Thanks for pointig to EDEM cal I had no idea about this. I have used static angle of repose test but like you said maybe I'll have to look into dynamic angle of test (probably have to set up an experiment).

1. But do we have tutorials for 'EDEM cal'?

2. How do I access EDEM cal?

Regards,

Kiran

Hi Kiran,

EDEMCal comes with the EDEM installation. The default installation path on Windows is: C:\Program Files\Altair\2023.1\EDEM\EDEMCal\bin

There's a EDEMCal tutorial on the Altair community. You can find it here

Best regards,
Renan