Page 171 - Thomson, William Tyrrell-Theory of Vibration with Applications-Taylor _ Francis (2010)

158 Systems with Two or More Degrees of Freedom Chap. 5

^ ^ — M
^ Figure 5.8-5. Untuned viscous
/nf))'nm rnnnm yrfh7i damper.
for any given ¡i, as shown in Fig. 5.8-4.

^0 (5.8-6)
i/2(T T 7o(yT 7iy
and that the peak amplitude for optimum damping is found at a frequency equal to

— = V2/(2 + m) (5.8-7)

These conclusions can be arrived at by observing that the curves of Fig. 5.8-3
all pass through a common point P, regardless of the numerical values of Thus,
by equating the equation for \K0^^/M\ for ^ = 0 and = oo, Eq. (5.8-7) is found.

Figure 5.8-6. Two-DOF building
model on a shaking table. {Courtesy
of UCSB Mechanical Engineering Un­
dergraduate Laboratory.)