Can you specify spring stiffness and damping as a curve instead of a single value ?

• Jun 29, 2020

• #2

GregLocock

Automotive

Apr 10, 2001

23,891

Orbiting a small yellow star

Assuming you are using View

The answer is yes. Non linear arrays of numbers can be entered directly, that's called a spline. So right click in the textbox by the K in the spring design box, choose parametize/exprsssion builder. Then you can use AKISPLINE to create a function to read your x and f arrays, which you will also need to create.



Cheers

Greg Locock


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• Jun 30, 2020

• Thread starter
• #3

Ionut Cosmin

Aerospace

Jul 22, 2016

24

RO

Hi Greg,

Yes, I am using View. I have tried using what you have mentioned, although I used AKIMA_SPLINE (because I cannot find AKISPLINE in the options, I am using MSC ADAMS 2014), but I get the following error:

I don't think the K coefficient accepts multiple values.

Thanks,
Cosmin

 

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• Jun 30, 2020

• #4

GregLocock

Automotive

Apr 10, 2001

23,891

Orbiting a small yellow star

AKIMA_SPLINE is the right one. So did you create x and F splines and refer to them in your expression?

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376

http://eng-tips.com/market.cfm?

 

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• Jul 2, 2020

• Thread starter
• #5

Ionut Cosmin

Aerospace

Jul 22, 2016

24

RO

Yes, now it works, I could not understand the independent variables at first but I have managed to sort it out. I created a measuring function with the following syntax: AKISPL(ABS( .damper_simplu.SPRING_1.deformation),.damper_simplu.SPRING_1.force ,SplineForce, 0) and now the simulation works.

Thanks a lot Greg!

Regards,
Cosmin

 

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• Jul 9, 2020

• #6

johnie134

Structural

Jan 1, 2020

75

GR

it is non-linear. very advanced for skilled enginners ONLY

 

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