Table for non-linear spring for using in PBUSHT

gopal_rathore

Hi,

Want to know about how to input a non-linear spring involving both tension and compression scenarios as table for PBUSHT property.

Any sign convention to be followed for it.

Currently I am entering force in Y axis and displacement in X axis, but getting absurd results which might be due to sign convention or axis selection etc.

 

Kindly let me know about it.

Altair Forum User

Hi Gopal,

 

You can have both tension and compression in PBUSHT card (force Vs Disp, KN line) through TABLED1 card. You can have negative and positive magnitudes.

 

Can you check if there are any discontinuities in tabled1 card?

 

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

gopal_rathore

Hi,

Thank you will check this.
Also when we take output for spring element forces, does the X, Y and Z correspond to the local coordinate system of spring or the global coordinate system?

Altair Forum User

Gopal,

 

It will be in global coordinate system unless the element system is different.

Altair Forum User

Hi prakash,

 

I want to define the force vs Displacement curve for spring elements and run the analysis can you please guide me how to define the cards and curves. If possible can you please share any model file. So that it will easy to understand.

 

Thanks 

 

Altair Forum User

Hi Dinesh,

 

You can use PBUSHT with KN field which helps to define force Vs Deflection curve. 

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

Altair Forum User

thanks prakash,

 

I have define the values in load collector and i have called the load collector in KN line but ii am getting the error as shown in below could you please help me how to define the table and whether selecting the table in to KN line procudure i am doing is right or wrong ?

 

 

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

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

Altair Forum User

Hi DInesh,

 

Can you activate K_Line and run the analysis?

Altair Forum User

Hi prakash ,

 

Even if i activate K Line, It giving same error.

 

 

Altair Forum User

Hi DInesh,

 

Can you share the model file using file transfer link in my signature below?

Altair Forum User

Hi Prakash,

 

Can you please tell how to define variable pressure in optistruct..

 

 

Altair Forum User

Hi DInesh,

 

Watch this video.

Unable to find an attachment - read this blog

Altair Forum User

Thanks prakash..

 

Altair Forum User

Hi Prakash ,

 

I have transfer the file....Please check once...

Altair Forum User

@dineshreddy

 

Thank you  I will check and update to you soon 

Altair Forum User

Dinesh,

Model is working fine at my end. Please let me know if you need any help. 

Altair Forum User

Hi prakash,

 

Do have any tutorial model for seal & pressure load case for BIW component 

Altair Forum User

Hi @dineshreddy

 

RIght now I don't, but I will check if there is any available from database. 

Altair Forum User

Thanks praksh 

 

Or if not possible can please some information about that load case

gopal_rathore

Hi,

Are you having force -displacement curve for different pressure cases as observed in air suspension of a vehicle?