Joint efficiencies in automotive chassis

[GregLocock]

I'm modelling a conventional ladder chassis using beam elements. I am only interested in the torsional stiffness between the spring towers.

Does anybody have any experience in estimating the joint efficiency of the various welded joints in this sort of structure?

I've x posted this to the FEA group, can we keep the replies here?

Cheers

Greg Locock

 

[btrueblood]

Greg,

I've only heard of joint efficiencies as an estimate of the failure strength of the weld joint (relative to parent metal). For a stiffness calculation, I'd just assume the weld joints are parent metal & go on. Or are you modelling the weld beads/spots too?

 

[GregLocock]

Yes, the welds are being modelled. I was particularly worried about how torsional loads would be transferred in a typical ladder chassis. As it turns out with a bit of intelligent design there is no particular problem when conventional engineering sections are used, and the chassis is stick welded.

The horror stories seem to come about with modern design and assembly techniques, with silly section shapes, spotwelds, and hence flanges, and fewer internal bulkheads.



Cheers

Greg Locock