For the clutch of Prob. 657, the external load P is cycled between 4.5 kips and 18
Question:
For the clutch of Prob. 6–57, the external load P is cycled between 4.5 kips and 18 kips. Assuming that the shaft is rotating synchronous with the external load cycle, estimate the number of cycles to failure. Use the modified Goodman fatigue failure criteria.
In Prob. 6–57, A schematic of a clutch-testing machine is shown. The steel shaft rotates at a constant speed ω. An axial load is applied to the shaft and is cycled from zero to P. The torque T induced by the clutch face onto the shaft is given by
T = f P(D + d)/4
Where D and d are defined in the figure and f is the coefficient of friction of the clutch face. The shaft is machined with Sy = 120 kpsi and Sut = 145 kpsi. The theoretical stress-concentration factors for the fillet are 3.0 and 1.8 for the axial and torsional loading, respectively. Assume the load variation P is synchronous with shaft rotation. With f = 0.3, find the maximum allowable load P such that the shaft will survive a minimum of 106 cycles with a factor of safety of 3. Use the modified Goodman criterion.
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Determine the corresponding factor of safety guarding against yielding.
Step by Step Answer:
From Prob 657 K 280 K 174 S 4512 kpsi min OmaxK 280 K Imax f Pmax In f Pmin min Ja ...View the full answer
Shigleys Mechanical Engineering Design
ISBN: 978-1121345317
9th edition
Authors: Richard G. Budynas, J. Keith Nisbett
