Cable-stayed bridges - Computational Analysis and Design of Bridge Structures - page 367

11.7 illustrated exaMPle With dynaMiC Mode
analysis of long CaBles With Crossties
In this example, cable stays in the main span side of a cable-stayed bridge
are modeled separately, as shown in Figure 11.20. It is modeled as 992 truss
elements and 963 nodes in total. The analysis was conducted by VBDS
(Wang and Fu 2005) and verified by ANSYS. The initial tensile forces of
crossties have the same value of 50 kN, which only serves the purpose of
tying down the main stays. The initial tensile forces of main cable stays are
obtained from a separated ideal state analysis, which range from 1532 to
4807 kN (344.4 to 1080.7 kip).
Figure 11.37 shows the first mode with a radian frequency of 5.39 rad/
sec ( f = 1.51 Hz). Figure 11.38 shows the second mode with a radian
Figure 11.37 The first mode of long cables with crossties (radian frequency = 5.39 rad/sec).
Figure 11.38 The second mode of long cables with crossties (radian frequency = 7.38 rad/sec).