Calculating Mating Force for snap fit 1

[Konsult]

Are there any formulas to calculate the Mating Force with friction when the part has an angle as shown in the picture below.

http://img147.imageshack.us/img147/8291/snapfitangelwh2.jpg

I haven't found any formulas which takes a angel like that in to consideration

Any answers are appriciated!

 

[unclesyd]

It looks like the insertion angle determines the insertion force. In your picture the angle of the post is the determining factor as you still have point contact.

http://engr.bd.psu.edu/pkoch/plasticdesign/snap_calc.htm

http://webtools.sabic-ip.com/webtools/redirect?tool=snapfit

 

[Cockroach]

You have what we call in the oilfield industry, a fingered collet. You can treat individual fingers as cantilever beams and apply such simple equations plus friction of wedged blocks. It is a problem of statics, found in most textbooks.

There are two types of collets, open and closed. The closed is modelled as a statically indeterminate beam, but otherwise operates the same. I've seen this problem handled as a circular beam in bending, Roarks also has some discussion on this with formulae in the table.

Also try the various oilfield technology companies website or forums. This is a typical application for downhole completions, packers, landing equipment, nipples, etc.

Good luck with your search or research!

Kenneth J Hueston, PEng
Principal
Sturni-Hueston Engineering Inc
Edmonton, Alberta Canada

 

[hydtools]

Try this ref for cantilevered lug solution?

http://www2.dupont.com/Plastics/en_US/assets/downloads/design/DCI385.pdf

Ted