vibration optimization

durukanbdilek

 

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 ?

 

 

 

best regards, thank you for quick response

Dhanasharee Jadhav_21915

Hi,

frequency u can give value based.

displacement constraint also can be applied in Inspire.

 

Regards,

Dhanasharee Jadhav 

 

durukanbdilek

Altair Forum User said:

Hi,

frequency u can give value based.

<?xml version="1.0" encoding="UTF-8"?>

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 A. Koga

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

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

/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 A. Koga

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

@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