Variable fillet to minimize stress concentration
Variable fillet to minimize stress concentration
(OP)
I am trying to find the description of the variable radius fillet that minimizes stress concentrations. I do not currently have access to Roark's or similar reference. Thank you.
Rob Stupplebeen
Rob Stupplebeen





RE: Variable fillet to minimize stress concentration
RE: Variable fillet to minimize stress concentration
I presume what Rstupplebeen is looking for is a "polycentric" fillet, i.e. a fillet beginning with a "big radius" and then ending with a "small radius" tangent to the first one.
This kind of fillet is very frequently used in steppings for power transmission shafts, and is the easiest "approximation" of an elliptical fillet (the polycentric one is much easier to machine with CNC machines).
Unfortunately, I don't have any theory reference about how to choose the two radii in order to minimize one (or more) of the SCFs. Where I work, the ratio btw the two radii has been standardized and what I make is usually only a verification of the resulting SCFs.
Regards
RE: Variable fillet to minimize stress concentration
http://www.esdu.com/graphics/dataitem/75033.htm
Mike Halloran
Pembroke Pines, FL, USA
RE: Variable fillet to minimize stress concentration
Robert Stupplebeen