= 85 kpsi). It is A 1-in-diameter solid round bar is made of AISI 1040 CD steel (sy = 71 kpsi, Su operating at a temperature of 300°F, and is subjected to a purely reversing torque of 2000 lbf.in. Estimate the number of cycles to failure if the expected reliability is 99%. Redo the solution for a reversing torque of 8500 lbf.in. Note: The Von Mises stress for pure torsion would be o' = √3T².

A device contains two bearings is to operate at 300 rev/min, 8 hours per day, 5 days per week for 5 years with a reliability of 0.99. The design load is (2006) N and an application factor of 1.2 is appropriate. Find the catalog rating C10            a)For ball bearings         b) For roller bearings  The Weibull parameters are x0=0.02 ,(θ-x0)=4.439 and b=1.483 Use SI units. Take the relations as C10=afFD[xD/x0+(θ-x0)(1-RD)1/b]1/a and xD=LDηD60/LR  Where the subscripts D: desired R: rating f: factor