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How to reduce penetration

Hello,

May I ask your favor regarding contact and reaction force?

1. Regarding contact (penetration)

1-1) I am solving excavator model which is passing over blocks. As you can see in below picture (section cut view to see penetration) there are several penetrations. I solved several times by changing contact stiffness K (F=K*z^exp) but those were not worked properly. I tried within 1000~3000 for K and time step 0.0005~0.0003 (too long solving time if use 0.0001). Can you advise me how to reduce penetration?

1-2) As you can see in picture in below right, too much penetration was made for 0.01 second. There are around 50 sub steps between 4.94 and 4.95 second. And average step size is 2.44E-5. Should I reduce step size more? or is there any reason and countermeasure for this kind of result?

1-3) I saw Advanced option panel for contact in MotionView. Is this helpful to resolve above problem? I tried with checking them but I was faced an error. Could you explain me the function of the option? or Could you let me know the link describing detail explanation?

2. Reaction force

I am comparing Roller's reaction forces between test and simulation. Reaction force by simulation is 2 or 3 times higher than that of test. All parts are composed by rigid body, including ground. Length of ground is around 30m and I installed bushing(3E5N/mm for translational, 1E15N/mm for rotational) on the ground to reduce reaction force but it was not enough to reduce reaction force (ground deflect too much if use weaker bushing). Do you have this kind of experience? and could you share the experience how did you resolve this kind of problem (very higher force than real)?

Thank you and Merry Christmas & Happy New Year.

Yoseob Shim

1

Re: Thermal modelling in Flux - Questions from a beginner

Hello Melih,

About your last request, you will find the example "Brushless IPM motor - thermal analysis" here: https://help.altair.com/flux/Flux/Help/english/UserGuide/English/topics/Examples2D_en.htm

The same example is also available from the Flux Supervisor; it explains the difference between steady state and transient computation. Models and related documents are also available.

Please, update the FluxMotor version if you have the opportunity to do it, version 2023 is available on our website.

Best regards,

Letizia

Letizia Ferrara

1

Re: Thermal modelling in Flux - Questions from a beginner

Hello Melih,

Below you will find answers to your questions.

1. Normally, these losses are computed within FluxMotor so you can take these values from the results you obtained from the working point computation.

2. with the "static thermal model you will have the Steady State application in the model, that means that you will find the steady state temperatures.

3. Yes, there is no automatic export for the transient thermal model.

You could export the "static model" and easily convert the application to transient directly in Flux: [Application --> Convert current application--> to Transient Thermal].

Please remember to add the "volumetric heat capacity" to the materials.

Best regards,

Letizia

Letizia Ferrara

1

Re: Altair Inspire® Challenge #6: Lilly Pad Optimization

Dear sir,

I have done optimization of Lilly pad in three different ways (by changing manufacturing constraints, and optimization settings). please check the results

Sakshi Patil

4

Re: Altair Inspire® Challenge #6: Lilly Pad Optimization

Re-done the challenge

Ripfumelo

1

how to set crontab for vovnotifyd for monitoring

Hi,

If we go 3 months without using vovnotifyd daemon , this daemon goes down and we need to start manually and then kick off a run using the mail notification –

Is there any way we could have a crontab monitoring the nc setup to check for that daemon every so often?

Regards

Pavan

Pavan K_21222

1

Do you want to learn more about HyperStudy Flux Connections? There is a dedicated eLearning module on learn.altair.com!

The eLearning module, HyperStudy Flux Connection, is now available on learn.altair.com!

In this module, we cover how to connect Flux to HyperStudy and use them together. This module is broken down into a short introduction and a demonstration on how to set up the connection between Flux and HyperStudy. Then some best practices when using this connection are illustrated. Finally, proposed exercises and links to Community posts are presented.

Want to get started? Click here to directly access this course.

liz_w

1

Re: Do the Absolute Error in Performance (Regression) is same as Means Absolute Error (MAE) ?

Hi @Afif,

Yes, this is the same value. As stated in the documentation, the absolute error is calculated by summing the differences between the labels and predictions, and dividing this value by the number of examples.

Best,

Roland

RolandJones

1

Re: Seems to be an issue with compatibility of PMSM (FluxMotor) block with LUTs exported from FluxMotor 2023

Hi all,

I'm getting in touch to offer a workaround for this issue. FYI we anticipate it will be resolved in FluxMotor 2024.

It seems the issue is due to a difference in the name of "iron losses" and "torque" headers.
With FluxMotor 2022.3 it was LOSS_IRON
with FluxMotor 2023, it is LOSS_IRON_STATOR.

______________________________________________________________________

With FluxMotor 2022.3 it was TORQUE
with FluxMotor 2023, it is ELEMENT_TORQUE_ELECTROMAG.

_______________________________________________________________________

As a workaround, you can open the .mat file exported from FluxMotor using Compose and the MAT Explorer tool. From there, you can rename the headers accordingly. Once modified, you should save the altered file using the save('path/name.mat') command.