Sheet metal Spring, Force to Compress To a smaller Diameter

[Zibraz]

I'm struggling to determine the force to reduce this sheetmetal spring to Ø17.8mm.

If someone could point me in the direction or give advice, that would be great. I can find alot about normal wire springs, but can't find much for a sheetmetal spring. The spring is 0.6mm thick and 10mm long.

Thanks!

 

[MintJulep]

Force applied where?

Reacted where?

Why would you think it will stay a circular arc when deflected?

 

[Zibraz]

Force applied where?

Reacted where?

Why would you think it will stay a circular arc when deflected?

This sheetmetal spring is going to be inserted into a cylinder with a Ø17.80 bore. So the whole diameter will be compressed. I want to know how much force will be exerted outwards into the walls of the cylinder (Or know how much force it needs to compress the diameter.

 

[dvd]

Include thickness tolerance range in your analysis.

 

[GregLocock]

So imagine a radial , distributed , load on the green bit. The change in curvature is uniform along the beam so it is tempting to jump to the useful beam equation M/I=E/R. The only unknown is M, the derivative of that is the shear force which is the load in the first sentence. I doubt it is constant but could be wrong.

 

[CWB1]

I would search Machinery's Handbook and other texts for clock springs, and if all else fails try Google.

 

[3DDave]

Since it isn't uniformly loaded it won't be uniformly curved, but basically it is closing a curved beam by the difference in diameters. I don't have curved beam formulae at hand, but they are easy to find.