The force required to compress a cylindrical solid between flat parallel dies (See Figure 18-10) has been estimated (by a theory of plasticity analysis) to be

where
R = radius of the cylinder
T = thickness of the cylinder
σ0 = yield strength
m = friction factor
An engineering student is attempting to impress his date by demonstrating some of the neat aspects of metal forming. He places a shiny penny between the platens of a 60,000-lb capacity press and proceeds to apply pressure. Assume that the coin has a 3/4-in. diameter and is 1/16 in. thick. The yield strength is estimated as 50,000 psi, and since no lubricant is applied, friction is that of complete sticking, or m = 1.0.
a. Compute the force required to induce plastic deformation.
b. If this force is greater than the capacity of the press (60,000 lb), compute the pressure when the full-capacity force of 60,000 lb is applied.

Transcribed Image Text:

1 2 mR