static stiffness testing of frame

[sasank]

Hallo!

can anybody tell me how an automotive frame (SUV or pickup)
tested for static stiffness? Can we simulate this in FEA? If so, what boundary conditions we have to use to get the FEA results close to real time testing.

Regards
sasank

 

[GregLocock]

For torsion we build a frame that connects the two rear spring towers that pivots in the middle. The front spring towers are then supported on stands.

A torque is then applied to the frame.

Note that the details of the test setup will affect the result.

Cheers

Greg Locock

 

[JakubMech]

There is a paper on this in regards to testing a nascar style racecar (winston?), and has verification with FEA and a simple box frame made up. Try to search for that, seems its exacly what your after.

JMech

 

[sasank]

Thanks for the information. But, I wnated to know, how do we get the individual bracketry stiffnesses measured during the test. What boundary conditions they use for testing.
Also, another question is suppose if we want the bending stiffness of BIW or frame to be say around 4000 N/mm, what is the justification for that number?

Regards
SAS

 

[GregLocock]

What sort of vehicle are you talking about?

Cheers

Greg Locock

 

[sasank]

it is in btween a an SUV and Pick Up. The nuber I gave is an arbitrary number. I wnated to know, how to fix the vertical bending stiffness target? what is the theory or justification for fixing a particular target nuber.

Regards
sasank

 

[GregLocock]

Durability, noise and vibration, squeaks and rattles, and ride and handling, will all have some say in that decision. I suggest you talk to your representatives in those groups, as it is a long subject, and has significant cost and weight implications.

Crash will also want to get involved, they'll want a weak structure, in opposition to everyone else.





Cheers

Greg Locock