410 A. Sharma et al. Fig. 42.5 Detail of hanger-beam contact for ‘hanger side’ case Fig. 42.6 Beam with hanger oriented to the front Fig. 42.7 Detail of hanger-beam contact for ‘hanger front’ case 42.4 Results A representative measurement of each beam is given in the following figures (Fig. 42.8, 42.9 and 42.10). As can be seen in Fig. 42.8, the response without hanger (beam only) has a higher frequency (47.51 Hz) as compared to the cases with a hanger. This was expected because the effective mass of beam is increased due to addition of hanger, and as the mass increases the frequency will decrease. The frequency of the ‘hanger side’ case is 11.03 Hz and the frequency of ‘hanger front’ case is 10.65 Hz which are very close. However, the type of damping and the value of damping ratio in these two cases are markedly different. The damping ratio of the ‘hanger front’ case is significantly higher than the ‘hanger side’ case. Another important observation is the mechanism of damping present in these two cases: the ‘hanger side’ case shows exponential decay, however, the ‘hanger front’ case seems to have linear decay. These observations will be further explored in the analysis section. Although the values of damping ratio differs between the beams in Figs. 42.8, 42.9 and 42.10, it can be definitely said that the beams follow a similar trend.
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