Cable-stayed bridges - Computational Analysis and Design of Bridge Structures - page 368

Figure 11.39 The eighth mode of long cables with crossties (radian frequency = 9.31 rad/sec).
frequency of 7.38 rad/sec ( f = 2.07 Hz). These two low-frequency
modes show the global movements of the cable net. At a higher mode,
the eighth mode has a radian frequency of 9.31 rad/sec ( f (f = 2.61 Hz); for
example, as shown in Figure 11.39, local movements of single cables will
appear.