Cylinders 2 Lecture 15 ME EN 372 Andrew Ning aning@byu.edu - PDF document

Cylinders 2 Lecture 15 ME EN 372 Andrew Ning aning@byu.edu Outline Shrink and Press Fits Shrink and Press Fits with Pressure

Shrink and Press Fits

� ( r 2 o − R 2 )( R 2 − r 2 i ) � p = Eδ o − r 2 2 R 3 r 2 i Equation is similar, but more complex, if the two cylinders use different material (Eq. 3-56 in Shigley) p p

Hoop stress ( σ θ ): c b a 0 Example A steel (E = 30 Mpsi, ν = 0.292) tire that is 3/8 inch think is shrunk over a cast-iron (E = 13 Mpsi, ν = 0 . 211 ) rim that 1 in thick with a diameter of 16 inches. The hoop stress in the tire must not exceed 20 kpsi. What is the inside diameter to which the tire must be bored?

Shrink and Press Fits with Pressure p

pressure vessel interference fit total hoop stress across entire cylinder c b + = a 0 P i P i