Determinig Potential Embedment

[MintJulep]

VDI 2230, in discussion of potential embedment within a joint states

The guide values given in Table 5.4/1 may be used
to estimate the amount of embedding of joints if no
values determined experimentally are available for
the respective case.

However, no guidance is offered as to how one might experimentally determine a value for a specific joint, nor is there any satisfactory explanation of where the values in table 5.4/1 come from.

Can anyone point me to some literature that might explain how the amount of potential embedment could be determined?

 

[MikeHalloran]

I've found them handy for other odd uses, but I can't quite understand why aluminum PEM studs exist.



Mike Halloran
Pembroke Pines, FL, USA

 

[MintJulep]

I could imagine them being used to hold circuit boards in an aluminum enclosure, possibly with a plastic nut.

How is this relevant to my question?

 

[MikeHalloran]

Aluminum PEM studs are just about impossible to actually embed in aluminum chassis. They're not noticeably harder than 5052-H32, let alone -H34.

That's what your question brought to mind.






Mike Halloran
Pembroke Pines, FL, USA

 

[CoryPad]

The reference for the data is:

Ba-Saleem, M.O.: Theoretische und experimentelle Untersuchungen der Setzverluste an Schraubenverbindungen. Dissertation Technische Universität Chemnitz 1991.

I don't know of any literature. The testing very likely involves taking blocks of known roughness, initial preload and displacement and moving them either axially (tension-compression) or transversely (shear) and then measure the residual preload and displacement after movement. I would conduct this type of testing on a Universal Testing Machine.

Regards,

Cory

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[MintJulep]

Thanks Cory,

I've already asked my librarian to see if she can track down an English translation of that reference and the one that follows it in the bibliography.