c) Increase all even-numbered masses by a factor of ten, plot the resulting natural
frequencies, mode shapes, and frequency response, and compare to (b). Now the
properties of the structure vary periodically in space, and gap(s) in the frequency
response – band gaps (Brillouin 1946; Jensen 2003; Sorokin and Thomsen
2015a, 2016) – should show up.
Fig. P1.10
48
1 Vibration Basics