Cancel
Showing results for 
Search instead for 
Did you mean: 

Freebody and Bolt Preload

Legend
Legend

Hello,

 

I made a simple model of bar elements and in the midle I used on an element 1000 N bolt preload and constrained both ends. After running the analysis I created freebodies:

 

Freebody_BoltPreload.jpg

 

All reaktion forces and internal forces are 1000 N except of element with bolt preload. On this element I got 12000 N (in reversed direction).

 

What is this 12000 N, which value?

 

I attached the model too.

 

Best regards

 

Peter Kaderasz

2 REPLIES

Re: Freebody and Bolt Preload

Legend
Legend

Hello,

 

nobody know answer to my question?

 

I made many analyzes in which I got irreal values of internal loads with help of Freebody, last time in Femap v11.4.2.

 

For example in test model of my previous post the internal load is -12000 N according to the Freebody and the Bar EndA Axial Force is 1000 N (rounded) on this element:

Freebody_BoltPreload and Bar EndA Axial Force.jpgFreebody Bolt Preload and Bar EndA Axial Force

 

Best regards

 

Peter Kaderasz

Re: Freebody and Bolt Preload

Solution Partner Phenom Solution Partner Phenom
Solution Partner Phenom

Dear Peter,

I get the same result, you need to play with FREEBODY CONTRIBUTIONS from Peripheral elements & Freebody elements:

  • Choosing the element neighbor to the bolt preload as freebody element you need to desactivate the option Peripheral element and activate Frebody element.

freebody-plot1.png

  • Choosing the proper bolt preloaded element#1 as Freebody element to get the axial force of 1000N at node#100 you need to activate contributions from Peripheral Elements and desactivate Freebody elements:

freebody-plot2.png

Best regards,
Blas.

Blas Molero Hidalgo, Ingeniero Industrial, Director
IBERISA • 48004 BILBAO (SPAIN)
WEB: http://www.iberisa.com
Blog Femap-NX Nastran: http://iberisa.wordpress.com/