interface pressure and possible torque - LamT's equations
interface pressure and possible torque - LamT's equations
(OP)
I've found the formulas (see attached pdf-file) in thread 1090698.
However could someone confirm those, or can provide a source?
I've checked Roark's but it isn't mentiond (the section "thermal stresses" is rather limited).
Machinist's handbook also doesn't give the formule for two different materials.
Problem is that it differs 10^6 even with being consistent in N and mm and mm², and that the found value seems rather high (even when divided by 10^6).
Am I using the correct formula? all opinions are much appreciated...
The application is a brass knob (22-40 dia) which needs to be heated and fitted to a steel shaft (14-22 mm dia) with a total interference of about 0.03 mm (tolerance is 22R8 on the knob).
Thanks.
However could someone confirm those, or can provide a source?
I've checked Roark's but it isn't mentiond (the section "thermal stresses" is rather limited).
Machinist's handbook also doesn't give the formule for two different materials.
Problem is that it differs 10^6 even with being consistent in N and mm and mm², and that the found value seems rather high (even when divided by 10^6).
Am I using the correct formula? all opinions are much appreciated...
The application is a brass knob (22-40 dia) which needs to be heated and fitted to a steel shaft (14-22 mm dia) with a total interference of about 0.03 mm (tolerance is 22R8 on the knob).
Thanks.





RE: interface pressure and possible torque - LamT's equations
RE: interface pressure and possible torque - LamT's equations
I found sources for 0.05-0.10 and other says around 0.35.
This is less critical, as even with 0.05 the torque would suffice for this application - I'm just being curious.
RE: interface pressure and possible torque - LamT's equations
Any comments on the correctness of the formula (although now I seem to have rather correct values)
and about the COF ?
RE: interface pressure and possible torque - LamT's equations
COF (steel-brass): 0.35 (dry clean surfaces) - 0.19 (lubricated)
RE: interface pressure and possible torque - LamT's equations
http://ww
That formula gives the exact same results as the tribology calculator
http://www.tribology-abc.com/calculators/e3_8.htm
so I believe it to be correct.
So I believe either I misinterpreted something, or the formula given in that thread contains an error (in the denominator, there are two "[" but only "]" ???
That formula can be found here:
ht
RE: interface pressure and possible torque - LamT's equations
RE: interface pressure and possible torque - LamT's equations
This would be the correct formula: see attached file.
RE: interface pressure and possible torque - LamT's equations
Kenneth J Hueston, PEng
Principal
Sturni-Hueston Engineering Inc
Edmonton, Alberta Canada
RE: interface pressure and possible torque - LamT's equations
Hence my question, as there was a 20+ % difference with the on-line calculator (tribology website) I referred to above.