An automatic transmission receives as an input 422 ft-lb of torque from the torque converter.
A multi-disc clutch is to be designed to transmit this torque to the planetary gear sets. The clutch rings have outer and inner diameters of 6.0 in. and 5.75 in., respectively.
The friction material is to be sintered metal, operated wet, giving the surface a coefficient of friction of 0.08 with a maximum allowable applied pressure of 500 psi. How many two-sided discs are required for this application? Assume uniform wear. (Answer: Four.)