solid metal ball design
solid metal ball design
(OP)
Hi, i am designing a mechanism, which includes the metal balls (as that of ball bearing). The ball has to withstand two point load acting on its surface. Can anyone provide me a direction to do so.





RE: solid metal ball design
Manufacturing?
what are you looking for?
RE: solid metal ball design
RE: solid metal ball design
for allowable stress, maybe use 1.6 x Sallow as in the ASME Code
RE: solid metal ball design
Thanks for reply, i am interested in design. Where i can find Roark Table. ?
RE: solid metal ball design
This is the greatest book ever published in the history of the universe [if you're an ME, that is!! If the ship is sinking, this is the one you bring on the lifeboat to the desert island ;) - maybe Machinery's Handbook, too].
Remember when you watched the back of the professor's head for 4 years when he derived all those equations? Well, Roark has just the results & a lot more too.
Even if you're a high-tech FEA guy, it is great to verify solutions [i.e., "the FEA model produced results within 10% of Roark, so it must be right."]
Get a copy if you can. I think it's up to the 7th edition now - BUT - if you come across Grandpa's old 3rd or 4th edition hang on to that too, because some of the older formulae are more "user friendly" when you want a quick answer.
RE: solid metal ball design
Lists contact stress between a sphere and a flat surface as:
Po=0.616*(P/R**2*((E1*E2)/(E1+E2))**2)**3
Po max copressive stress
P=load
R=Rad sphere
RE: solid metal ball design
It's sounds like Hertz contact problem. Theoretical background and maths formulas you can find in : Thimoshenko, "Theory of Elasticy"
RE: solid metal ball design
Now, if there are three point forces, instead of two. is there any solution for finding stresses in metal ball(sphere). or method to find out the dia of ball based on these three forces.
RE: solid metal ball design
If there is friction (there is bound to be..), you can still work with the Herz formulas, but you will have to take into account that there is shear-stress in the surface. Thimoshenko might have something on that. You might elaborate a bit on the mechanism you are designing so we can have some idea of the forces, dimensions etc.
Regards,
Pekelder