Secondary pulley radius exceeded its maximum value.

sudo
sudo Altair Community Member
in Community Q&A

I am performing a simulation of an automatic motorcycle with a CVT and gathering its data. I checked the configuration of the cvt, and it states that the maximum running radius of the secondary pulley is 55 mm. However, when I reviewed the data collected after the simulation, I noticed that in the first few records, the secondary pulley radius reached 58 mm. I’m not sure if this is a bug or if there is a specific reason for it.

This is from the cetrifugal_rubber_belt.cvt:

image.png

This is from the data that I collected:

image.png

Thanks!

Best Answer

  • Orestis_YB
    Orestis_YB
    Altair Employee
    Answer ✓

    Hello @sudo,

    Rmin and Rmax values in cvt file are used to saturate the radius ratio. They will not saturate the actual radius of the pulleys. These radius are calculated based on the center distance of the pulleys and the belt length.

    Hope this helps!

    Best regards,
    Orestes

Answers

  • GTT Adam
    GTT Adam
    Altair Employee

    Hi @sudo,

    You are correct in that the limits set in the CVT file should restrict the pulley radii.

    How are you measuring the Primary Pulley and Secondary Pulley radii? Are you using the predefined Output or did you create one?

    image.png

    Hope this helps!

    Adam Reid

  • sudo
    sudo Altair Community Member
    edited April 6

    Hi @GTT Adam

    Yes, I am using that predefined Output.

    After the simulation, I used hypergraph to plot the data and export them as csv file. I selected that Pulley radii [F2 = Primary, F3 = Secondary] and selected F2 and F3 in the components selection.

  • GTT Adam
    GTT Adam
    Altair Employee

    Hi @sudo,

    Ok, perfect.

    Does this maximum pulley radii violation only happen at time = 0, or does it happen throughout the simulation? Can you share a plot of the pulley radii throughout the event you are completing?

    Hope this helps!

    Adam Reid

  • sudo
    sudo Altair Community Member

    Hi @GTT Adam

    Here is the link of the data that we gathered in a csv file format:
    https://drive.google.com/file/d/1z2ghNRkmnZQkVK2UVVCxq8WusLKkFNfw/view?usp=sharing

    Also here is the plt and abf files:

    scooter_Run_throffturninl_0.abf
    scooter_Run_throffturninl_0.plt
  • GTT Adam
    GTT Adam
    Altair Employee

    Hi @sudo,

    Are you able to attach the model as a zipped model archive?

    (File >> Export >> Model >> Archive Model & Create Zip File)

    Hope this helps!

    Adam Reid

  • Orestis_YB
    Orestis_YB
    Altair Employee
    Answer ✓

    Hello @sudo,

    Rmin and Rmax values in cvt file are used to saturate the radius ratio. They will not saturate the actual radius of the pulleys. These radius are calculated based on the center distance of the pulleys and the belt length.

    Hope this helps!

    Best regards,
    Orestes

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