convert linear force to radial force for compression with O-Ring
convert linear force to radial force for compression with O-Ring
(OP)
I'm using an O-ring as a belt (not a drive belt, like a waist belt), and I want to determine the compressive force that I am applying to the mandrel (or "waist" if we want to stick with that terminology).
I can easily take the length of the O-ring (if unraveled), the length (circumference) of the mandrel, and calculate a strain from those lengths. Where I have an issue is converting that linear load to a radial one.
I know I've seen this equation somewhere ( i thought it was in pressure vessel literature) but can't seem to find it.
Any + All help appreciated, thanks.
I can easily take the length of the O-ring (if unraveled), the length (circumference) of the mandrel, and calculate a strain from those lengths. Where I have an issue is converting that linear load to a radial one.
I know I've seen this equation somewhere ( i thought it was in pressure vessel literature) but can't seem to find it.
Any + All help appreciated, thanks.
Chris Loughnane - Product Design
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RE: convert linear force to radial force for compression with O-Ring
Eastbound you have two concentrated forces acting, these each being the tension (T) in the O-ring.
Westbound, you have the continuous "pressure" loading of the contact force (p – expressed as a force per unit length) directed radially. The vector integral, the "resultant", of this 180 degrees of radial force is easily shown to be equal to pD where D is the diameter of the O-ring, and this resultant has a direction due West. (If you have trouble with this result, think about Archimedes Principle and fluid pressure loadings.)
East-West equilibrium (a good thing in engineering as well as in politics) then tells you that
2T = pD
which is doubtless the formula you have at the back of your mind.
RE: convert linear force to radial force for compression with O-Ring
Cheers
Greg Locock
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