Stress Relaxation 1

[MintJulep]

Can anyone point me towards some literature on stress relaxation in bolted joints at non-elevated (150F ish) temperature?

Google returns too many hits for aroma-therapy, massage oil and new-age music.

 

[metengr]

Go to the web site below and download this book. Relaxation is dicussed in section 4.4

http://www.boltcouncil.org/guide1.htm

 

[MintJulep]

Looks like an excellent general reference.

I was hoping for some more nitty-grittyon stress relaxation, but it provides a few leads towards some research.

Thanks.

 

[Goahead]

The ASM Desk Edition has some articles on Stress Relaxation.
It reports relevant ASTM tests. Although the temperature looks low, maybe some tests should be performed to determine if there is a problem in the specific application.

http://www.welding-advisers.com/

 

[CoryPad]

The first two references of faq725-600 have good information regarding relaxation.

Regards,

Cory

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

 

[MintJulep]

Goahead,

No need for tests, the problem is clear. Too many layers of soft crap in the joint. I need some strong citable references to bolster my attempts to convince a client that soft "locking tab" washers are detrimental to joint performance.

Cory,

Thanks. I have VDI 2230 on my desk, it's on my list of things to read and understand one of these days. The parts on embedment and relaxation proved interesting to my immediate crisis.

I have an earlier edition of Bickford's Introduction to ...Bolted Joints. Is there anything in the Bickford and Nasser book that is not in that?

 

[Hansmeister]

In metal-to-metal joints, the relaxation is in the order of 2% per year. In composites, its an exponential decay, with about 40% relaxation the first year. The data is in an ASTM STP. If you desire, I can find the reference and post here.

 

[CoryPad]

MintJulep,

Sorry for the delay in answering your question. Handbook of Bolts and Bolted Joints does not have significant additional information regarding relaxation when compared to An Introduction to the Design and Behavior of Bolted Joints. There are some small items, but they are related to VDI 2230, so you are covered there.

Regards,

Cory

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