T1-19 Another property of mesh mounts is demonstrated by Figure 26 [5]. As can be seen, in practice there is a sudden sharp drop from the resonant point, ensuring that isolation is achieved almost immediately. However, it is again safer to assume that isolation does not begin until   2 f_n is achieved. 5.0    MULTIDEGREE OF FREEDOM SYSTEMS, COUPLED MODES Figure 27 demonstrates that there are six independent ways in which a body can move; i.e., it has SIX DEGREES OF FREEDOM. The reader must be aware from this that there is a potential of six independent natural frequencies, as well as possible coupled modes of vibration. Figure 27    Degrees of Freedom of a Solid Body Lateral Roll Yaw Vertical Vertical Pitch Fore and Aft or Longitudinal Figure 26    Theoretical Frequency Response Curve for a Hardening Spring Type Resonant System The hatched areas indicate the region of instability. a 1 2 3 4 f Free vibration "backbone"