b) Modal frequency
, using the matrix iterative method, which according to Rao (2009) determines various natural frequencies of vibration, starting from the lowest one, associating to each frequency the results of total displacement/deformation.
Transmissibility between Mounting Brackets and Chassis In order to find out the transmissibility, modal frequency
response analysis has been performed.
The vibration mode of unstable modal frequency
at 12,752.6 Hz is extracted from the results of complex modal analysis, as shown in Figure 13.
Table 5 shows the modal frequency
of the first two orders of the unit.
A damping ratio of 3% was chosen because of its strong agreement with the experimental results of the modal frequency
of the cables.
where E, [eta], [rho], I, and H are the elastic modulus, loss factor, density, length, and thickness of the beam, respectively, and [f.sub.n] and [DELTA][f.sub.n] denote the nth modal frequency
and half-power bandwidth, respectively and [C.sub.n] is a coefficient for mode n.
Miyamoto  studied the performance of unbonded pre-stressed concrete beams, provided the formula of beam modal frequency
in the case of a given pre-stress value and used the results of experiments and tests for correction.
Accordingly, the first significant modal frequency
is that of mode 7, in a set of 74 modes whose frequencies range from nearly 60 Hz up to approximately 1.2 kHz, as indicated in Table 1.
[w.sub.dk] and [w.sub.k] are undamped modal frequency
and damping modal frequencies of k order.
Previous researches have mainly optimized aircraft structures from the perspectives of both static and dynamic constraints such as stress, displacement, modal frequency
, and flutter constraints; see, for example, the previous publications by Sikes et al.
responses and displacements for stiffness were extracted from ASCII (American Standard Code for Information Interchange) output files.
Yen, "A story damage index of seismically-excited buildings based on modal frequency
and mode shape," Engineering Structures, vol.