vibration optimization

durukanbdilek
durukanbdilek Altair Community Member
edited October 2020 in Community Q&A

 

I would like to conduct a gauge optimization. In the optimization I intend to realize, I would like to minimize the vibration acceleration

 I would like to define the following constraint

  1. Let the acceleration value be lower than 0.125g (1.23 ms-2) at a frequency 3 times the mod frequency
  2. also, I would like to a define the vibration displacement in terms of natural frequency using an equation which was attached.
  3. finally I would like to define the equation as a constraint

 

How can I define these constraint ?

 

resim.png.44dd3df85844079b7be11bdc5af394f1.png

 

 

best regards, thank you for quick response

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Answers

  • Dhanasharee Jadhav_21915
    Dhanasharee Jadhav_21915 New Altair Community Member
    edited September 2020

    Hi,

    frequency u can give value based.
    image.jpeg
    displacement constraint also can be applied in Inspire.
     
    Regards,
    Dhanasharee Jadhav 
     
  • durukanbdilek
    durukanbdilek Altair Community Member
    edited September 2020
    Altair Forum User said:

    Hi,

    frequency u can give value based.
    <?xml version="1.0" encoding="UTF-8"?>image.jpeg
    displacement constraint also can be applied in Inspire.
     
    Regards,
    Dhanasharee Jadhav 
     

    Maybe, I could not tell my self. I will create a equation and this equation depend on frequency and this equation yields displacement

    and I want to define displacement constraint according to this equation

  • Adriano_Koga
    Adriano_Koga
    Altair Employee
    edited September 2020
    Altair Forum User said:

    • Let the acceleration value be lower than 0.125g (1.23 ms-2) at a frequency 3 times the mod frequency
    • also, I would like to a define the vibration displacement in terms of natural frequency using an equation which was attached.
    • finally I would like to define the equation as a constraint

     

    Hi /profile/32816-durukanbdilek/?do=hovercard' data-mentionid='32816' href='<___base_url___>/profile/32816-durukanbdilek/' rel=''>@durukanbdilek 

     

    One way of creating a more complicated equation in OS Optiization is though usage of DRESP3, using external softwares for calculating them, such as Altair Compose.

    DRESP3 adds these external libraries, and brings them as a response for OptiStruct.

    In the attached example, I've used a DRESP3 with Compose, to calculate wheel stiffness.

    This is basically takes the valley of some frequency range, and using this frequency computes some stiffness. In this case i've used Compose to do that, as it has more resources for working with curves as in your case.

     

    try this in your case.

    Unable to find an attachment - read this blog

  • durukanbdilek
    durukanbdilek Altair Community Member
    edited September 2020
    Altair Forum User said:

    One way of creating a more complicated equation in OS Optiization is though usage of DRESP3, using external softwares for calculating them, such as Altair Compose

    I have no altair compose  DRESP3 can be created with Excel how to create

  • durukanbdilek
    durukanbdilek Altair Community Member
    edited September 2020

    /profile/97129-adriano-a-koga/?do=hovercard' data-mentionid='97129' href='<___base_url___>/profile/97129-adriano-a-koga/' rel=''>@Adriano A. Koga

     

    I want this 'Let the acceleration value be lower than 0.125g (1.23 ms-2) at a frequency 3 times the mod frequency'

    how to perform it

    can you explanin step by step

     

  • Adriano_Koga
    Adriano_Koga
    Altair Employee
    edited September 2020

    I don't have an answer for Excel.

    But i'm adding a few examples of DRESP3 with Excel here.

     

    You will probabely need:

    - DRESP1 for the Frequency of mode 'X'

    - DRESP1 for FRF acceleration/displacement with frequency range enough to capture 3x the freq of interest

    - EXCEL spreadsheet calculating your response from a given input vector (from your FRF) and a frequency (freq of mode x)

    - loadlib to load your EXCEL spreadsheet

    - DRESP3 to link your EXCEL with your DRESP1's in the correct order

     

    You need to take care with the size of the vectors that you're looking for.

    Your eExcel has to include the logic for finding the value corresponding the 3x frequency.

     

    That's all I can do for you. 

    Now you need to build some test model (just a small one, ot your full model) and then experiment on it, and make sure your excel is working accordingly.

    Go through the OS help on 'DRESP3' as well for additional info.

     

     

    Unable to find an attachment - read this blog

  • Hüsnü Yalınkılıc
    Hüsnü Yalınkılıc Altair Community Member
    edited October 2020

    @Adriano A. Koga I cannot this 

    Let's simplify the problem
     
    if I want to minimize the vibration amplitude at any modes how to perform this
     

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