Pitch Distance
Pitch Distance
(OP)
Hello Everybody,
I would like to have the clarification on the effect of pitch distance in stress analysis. I have fitting which needs get connected through fasteners of 4.80 mm dia. The normal pitch kept is 4.5d-5.0d. In this case, due to space constraint, the pitch is 3.5d. The fasteners are shear loaded. How does it affect the stress results? Thanks in advance.
I would like to have the clarification on the effect of pitch distance in stress analysis. I have fitting which needs get connected through fasteners of 4.80 mm dia. The normal pitch kept is 4.5d-5.0d. In this case, due to space constraint, the pitch is 3.5d. The fasteners are shear loaded. How does it affect the stress results? Thanks in advance.





RE: Pitch Distance
RE: Pitch Distance
RE: Pitch Distance
RE: Pitch Distance
RE: Pitch Distance
Don't you mean 4.8mm = 3/16"?
tg
RE: Pitch Distance
RE: Pitch Distance
As 737eng says, changing the pitching of fasteners in a fitting can vary the load distribution between the fasteners, as well as the reactions to applied loads which may have a component parallel to, but displaced away from the mating surfaces.
Without knowing what the fitting looks like, I recommend that you consider performing a bolt group analysis (perhaps even a 3D one if necessary) using unit applied loads (in appropriate directions) to determine comparative fastener loads between the nominal and the varied configurations.
Regards
Graeme
RE: Pitch Distance
Biggest influence is that more fasteners = more weight = less efficient. Unless you have an inter-rivet buckling issue (comp loading) or bearing-bypass 'interaction' concerns the best-practice is to revert to 5d or thereabouts.
Aerodesign