Screw thread theory

[james2007]

Hi,

I am looking for a proof of why the first engaged thread of a uniform threaded connector takes the highest proportion of preload, followed by the second, then the third etc.

Is anyone aware of the theory behind the stress distribution in threaded connectors?

Many thanks in advance for your help.

James

 

[CoryPad]

The theory is force transfer through redundant paths. A thread can be thought of as a series of cylindrical grooves that are subjected to the same force. The first thread has the shortest path and is the stiffest, therefore it takes the highest proportion of the applied force.

Journal articles have the best information on this.

Journal of Mechanical Design v125 (2003) 527-532

Nuclear Engineering & Design 191 (1999) 109–116

Engineering Failure Analysis 12 (2005) 604-615

 

[unclesyd]

If you need to get copies of the Journal Articles in CoryPad's post here is good place to get copies for very nominal fee.

http://www.lindahall.org/services/document_delivery/

 

[james2007]

Thanks!

James