A more elaborate, if undamped, model of the press described in Exercise 2.29 is shown in Fig. 5.24. For the case in which ω = 10√k/m, find the amplitude of the oscillations undergone by the mass at the right.

Data From in Exercise 2.29

A simple model of the mechanism of a press is shown in Fig. 2.81. In this model, the Scotch yoke of the left is driven by a crank that turns at a constant angular speed ω, while the spring is undeformed when x = 0 and y = 0.

Under the current design it has been found that, when ω = √k/m, the mass oscillates with an amplitude M = 5l. From this observation, can you estimate the damping ratio ζ?

A modification is being proposed, that consists of changing the spring to one with a new stiffness knew. Choose knew, without modifying c, so that the amplitudes of the oscillations of the mass and the Scotch yoke coincide.

Transcribed Image Text:

3 Y k C X Fig. 2.81 A simplified model of a press mechanism m &